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30 Oct 2006

Volume 89, Issue 18, Articles (18xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 89, 181101 (2006); http://dx.doi.org/10.1063/1.2372737 (3 pages)

Z. D. Gao, S. N. Zhu, Shih-Yu Tu, and A. H. Kung
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Patterning the organic electrodes of all-organic thin film transistors with a simple spray printing technique

Yunseok Jang, Yeong Don Park, Jung Ah Lim, Hwa Sung Lee, Wi Hyoung Lee, and Kilwon Cho

Appl. Phys. Lett. 89, 183501 (2006); http://dx.doi.org/10.1063/1.2372583 (3 pages) | Cited 7 times

Online Publication Date: 30 October 2006

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The authors have demonstrated the application of spray printing technique for patterning organic electrodes of all-organic transistor on flexible polymeric substrate. Our spray printing technique is a simple, fast, and easy patterning process. The performance of the device obtained with the spray printing technique is shown to be comparable to that of the device with deposited metal electrodes (gold). Thus this spray printing technique provides a method for patterning the electrodes of all-organic transistors.
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85.30.Tv Field effect devices

Electrical bistability by self-assembled gold nanoparticles in organic diodes

H. P. Wang, S. Pigeon, R. Izquierdo, and R. Martel

Appl. Phys. Lett. 89, 183502 (2006); http://dx.doi.org/10.1063/1.2372688 (3 pages) | Cited 19 times

Online Publication Date: 30 October 2006

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Electrical bistability is reported in metal-organic-metal diodes. The device consists of two Al electrodes separated by a layer of 2-amino-4,5-imidazoledicarbonitrile that contains embedded Au nanoparticles (NPs) supported by parylene nanopillars. Electrical characterization of the device shows two well-defined states with high (off) and low (on) impedances. The on/off ratio is about 104. This conspicuous memory effect is rationalized in terms of charge storage mediated by the NP states. The fabrication method is general and provides a good control on both the size uniformity and the self-assembly of Au NPs embedded in the organic materials.
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85.60.Jb Light-emitting devices

Patterning of organic thin film transistors by oxygen plasma etch

Soeren Steudel, Kris Myny, Stijn De Vusser, Jan Genoe, and Paul Heremans

Appl. Phys. Lett. 89, 183503 (2006); http://dx.doi.org/10.1063/1.2374679 (3 pages) | Cited 14 times

Online Publication Date: 31 October 2006

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All applications of organic thin film transistors require patterning of the organic thin film to achieve a low off current and to prevent cross talk between neighboring transistors. A common method for patterning consists of using a protective layer and etching the uncovered small molecule film by oxygen plasma. One of the handicaps of this process is the observed degradation of the transistor characteristics. By varying the resist overlap, the authors show that the main cause of this performance degradation is, in fact, a far-reaching underetch of the oxygen plasma which can be overcome by choosing the right geometry of the resist pattern.
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85.30.Tv Field effect devices
81.16.Rf Micro- and nanoscale pattern formation
81.65.Cf Surface cleaning, etching, patterning
81.16.Nd Micro- and nanolithography

Sodium chloride sensing by using a near-field microwave microprobe

Arsen Babajanyan, Jongchul Kim, Songhui Kim, Kiejin Lee, and Barry Friedman

Appl. Phys. Lett. 89, 183504 (2006); http://dx.doi.org/10.1063/1.2374681 (3 pages) | Cited 8 times

Online Publication Date: 31 October 2006

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The authors observed the NaCl concentration of solutions using a near-field microwave microprobe (NFMM). Instead of the usual technique, they take advantage of the noncontact evaluation capabilities of a NFMM. A NFMM with a high Q dielectric resonator allows observation of small variations of the permittivity due to changes in the NaCl concentration. By measuring the reflection coefficient S11, they could observe the concentration of NaCl. The measured signal-to-noise was about 53 dB and the minimum detectible signal was about 0.005 dB/(mg/ml). In order to determine the probe selectivity, they measured a mixture solution of NaCl and glucose.
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07.07.Df Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing
85.50.-n Dielectric, ferroelectric, and piezoelectric devices
77.22.Ch Permittivity (dielectric function)

Acoustic streaming pattern induced by longitudinal ultrasonic vibration in an open channel using particle imaging velocimetry

Byoung-Gook Loh, Dong-Ryul Lee, and Kijung Kwon

Appl. Phys. Lett. 89, 183505 (2006); http://dx.doi.org/10.1063/1.2374683 (3 pages) | Cited 9 times

Online Publication Date: 31 October 2006

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Acoustic streaming, which is induced in an open channel by a cylindrical exciter vibrating at 30 kHz, is experimentally investigated using particle imaging velocimetry. Induced streaming pattern and velocity field for the channel gap of 18 mm are presented. The symmetric distinctive steady rotational flow with local eddies is observed. The maximum streaming velocity measured stands at 0.16 cm/s with a vibration amplitude of 50 μm at an excitation frequency of 30 kHz.
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47.54.De Experimental aspects
47.35.Rs Sound waves
47.60.-i Flow phenomena in quasi-one-dimensional systems
47.80.Jk Flow visualization and imaging
47.32.Ef Rotating and swirling flows

High temperature integrated ultrasonic shear wave probes

C.-K. Jen, Y. Ono, and M. Kobayashi

Appl. Phys. Lett. 89, 183506 (2006); http://dx.doi.org/10.1063/1.2374684 (3 pages) | Cited 1 time

Online Publication Date: 31 October 2006

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Integrated ultrasonic shear wave probes have been fabricated using steel substrates through a paint-on method with the use of mode conversion from longitudinal to shear waves. The probe can be operated up to 150 °C. A probe simultaneously generating and receiving both longitudinal and shear waves is also demonstrated.
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Coherent near-infrared wavelength conversion in semiconductor quantum cascade lasers

C. Zervos, M. D. Frogley, C. C. Phillips, D. O. Kundys, L. R. Wilson, J. W. Cockburn, M. Hopkinson, and M. S. Skolnick

Appl. Phys. Lett. 89, 183507 (2006); http://dx.doi.org/10.1063/1.2374842 (3 pages) | Cited 2 times

Online Publication Date: 31 October 2006

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A scheme for generating coherent “sidebands” on a near-infrared optical carrier beam is demonstrated experimentally, using a modified quantum cascade laser. The active region of the laser simultaneously provides the gain, generates one of the optical fields, and provides a doubly resonant second-order nonlinear optical medium. This allows coherent sideband generation with normal incidence coupling and with interaction lengths sufficiently short to be immune to phase-matching problems. The resulting electrically modulatable two-terminal device offers a means of performing various all-optical routing, switching, and detection operations of interest for optical telecommunications.
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42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
42.79.Nv Optical frequency converters
42.60.Fc Modulation, tuning, and mode locking

All-organic hot-carrier triodes with thin-film metal base

Tzu-Min Ou, Shiau-Shin Cheng, Chun-Yuan Huang, Meng-Chyi Wu, I-Min Chan, Shih-Yen Lin, and Yi-Jen Chan

Appl. Phys. Lett. 89, 183508 (2006); http://dx.doi.org/10.1063/1.2382745 (3 pages) | Cited 5 times

Online Publication Date: 31 October 2006

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In this letter, the authors investigate the promising vertical-type triodes based on small organic molecules and the related hot-carrier transport. The devices show transistorlike characteristics, in which output current can be modulated by demanding different input currents on their thin metal base electrodes. By using pentacene for the channel layer material and N,N′-di(naphthalen-l-yl)-N,N′-diphenyl-benzidine for the carrier energy-enhancing layer, the vertical-type hot carrier triodes exhibit a good current saturation with current gain of 2.38 for both the common-base and common-emitter configurations. The mechanism of operation is proposed and examined by the basic electrical measurements.
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85.65.+h Molecular electronic devices
84.47.+w Vacuum tubes

Improved performance of planar GaN-based p-i-n photodetectors with Mg-implanted isolation ring

M. C. Chen, J. K. Sheu, M. L. Lee, C. J. Tun, and G. C. Chi

Appl. Phys. Lett. 89, 183509 (2006); http://dx.doi.org/10.1063/1.2372767 (3 pages) | Cited 1 time

Online Publication Date: 1 November 2006

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This study analyzes planar GaN p-i-n photodetectors (PDs) fabricated using Si implantation. The authors have used triple silicon implantation to form a selective n+ channel, acting like a contact wire to connect the underlying n layer and the n contact located on the surface, through a GaN-based p-i-n structure. In order to suppress the lateral current conduction from the n contact to p contact, an extra Mg-implanted isolation ring between the n+ channel and the active p-i-n layers was also performed to achieve improvement of device performance. Typical peak responsivity and cutoff wavelength of Si-implanted planar p-i-n PDs were around 0.11 A/W and 365 nm, respectively.
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85.60.Gz Photodetectors (including infrared and CCD detectors)

Encapsulation-free hybrid organic-inorganic light-emitting diodes

Katsuyuki Morii, Masaya Ishida, Takeshi Takashima, Tatsuya Shimoda, Qing Wang, Md. Khaja Nazeeruddin, and Michael Grätzel

Appl. Phys. Lett. 89, 183510 (2006); http://dx.doi.org/10.1063/1.2374812 (3 pages) | Cited 42 times

Online Publication Date: 1 November 2006

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The authors have fabricated encapsulation-free hybrid organic inorganic light-emitting diodes (HOILEDs), with improved air stability performance by incorporating two different metal oxide layers. One metal oxide layer is a titanium dioxide layer that provides the electron-injection layer, and the other is a molybdenum oxide that injects holes. While our HOILED device exhibits a lower threshold voltage and a higher air stability than conventional devices using a Ca/Al cathode, a similar luminance output was observed.
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85.60.Jb Light-emitting devices

Vertical organic triodes with a high current gain operated in saturation region

Chuan-Yi Yang, Tzu-Min Ou, Shiau-Shin Cheng, Meng-Chyi Wu, Shih-Yen Lin, I-Min Chan, and Yi-Jen Chan

Appl. Phys. Lett. 89, 183511 (2006); http://dx.doi.org/10.1063/1.2374875 (3 pages) | Cited 11 times

Online Publication Date: 1 November 2006

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The authors report the fabrication of vertical organic triodes operated in the pronounced saturation regions by using two back-to-back pentacene Schottky diodes. The device with an optimized 0.7 nm LiF hole injection enhancement layer and a 70 nm pentacene emitter can achieve an ultrahigh common-emitter current gain of 48 in the saturation region at a low applied voltage VCE of −4 V and a base current density of 0.25 mA/cm2. In addition, the device exhibits a high output current density of 12.1 mA/cm2 and a high on/off current ratio of 103.
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85.30.Kk Junction diodes

Electron trapping and inversion layer formation in photoexcited metal-insulator-poly(3-hexylthiophene) capacitors

D. M. Taylor, J. A. Drysdale, I. Torres, and O. Fernández

Appl. Phys. Lett. 89, 183512 (2006); http://dx.doi.org/10.1063/1.2382727 (3 pages) | Cited 11 times

Online Publication Date: 1 November 2006

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Photocapacitance measurements are reported on metal-insulator-semiconductor (MIS) capacitors employing polyimide (PI) or polysilsesquioxane (PSQ) as the gate insulator and poly(3-hexylthiophene) as the active semiconductor. By stressing devices into depletion while simultaneously irradiating with light of energy exceeding the semiconductor band gap, photogenerated electrons become trapped at the insulator/semiconductor interface or possibly in bulk insulator states. Additionally for the PSQ device, evidence is provided for the formation of a photogenerated inversion layer at the interface. The time dependence of electron detrapping in the PI case is similar to that observed for accumulation stress instability in organic MIS devices.
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84.32.Tt Capacitors
85.30.Tv Field effect devices

White organic light-emitting diodes with fine chromaticity tuning via ultrathin layer position shifting

Hakim Choukri, Alexis Fischer, Sébastien Forget, Sébastien Chénais, Marie-Claude Castex, Dominique Adès, Alain Siove, and Bernard Geffroy

Appl. Phys. Lett. 89, 183513 (2006); http://dx.doi.org/10.1063/1.2382730 (3 pages) | Cited 29 times

Online Publication Date: 1 November 2006

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Nondoped white organic light-emitting diodes using an ultrathin yellow-emitting layer of rubrene (5,6,11,12-tetraphenylnaphtacene) inserted on either side of the interface between a hole-transporting 4,4′-bis[N-(1-naphtyl)-N-phenylamino]biphenyl (α-NPB) layer and a blue-emitting 4,4′-bis(2,2′-diphenylvinyl)-1,1′-biphenyl (DPVBi) layer are described. Both the thickness and the position of the rubrene layer allow fine chromaticity tuning from deep blue to pure yellow via bright white with CIE coordinates (x = 0.33, y = 0.32), an ηext of 1.9%, and a color rendering index of 70. Such a structure also provides an accurate sensing tool to measure the exciton diffusion length in both DPVBi and NPB (8.7 and 4.9 nm, respectively).
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85.60.Jb Light-emitting devices

Improvement of dichroic polymer dispersed liquid crystal performance using lift-off technique

A. Masutani, T. Roberts, B. Schüller, N. Hollfelder, P. Kilickiran, G. Nelles, A. Yasuda, and A. Sakaigawa

Appl. Phys. Lett. 89, 183514 (2006); http://dx.doi.org/10.1063/1.2372707 (2 pages) | Cited 11 times

Online Publication Date: 1 November 2006

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A lift-off method has been developed for the fabrication of polymer dispersed liquid crystal (PDLC) displays. A polymer matrix template can be prefabricated by lifting off a PDLC film from a fluorosilanized antisticking substrate. Desirable liquid crystal can then be backfilled/infiltrated into the template. Applying this technique to fabricate dichroic PDLC yielded a reflectivity of 66% and a contrast ratio of 13.8:1 in 3.8 in. quarter video graphics array reflective thin film transistor (TFT) displays. A diffuse layer with melamine-formaldehyde nanoparticles was employed to suppress the metallic glare caused by the reflective back plane. The technique is suitable for various back planes such as flexible, solvent/UV-sensitive, organic TFTs.
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42.79.Kr Display devices, liquid-crystal devices
85.60.Pg Display systems

Fabrication of highly efficient and stable doped red organic light-emitting device using 2-methyl-9,10-di(2-napthyl)anthracene and tris(8-hydroxyquinolinato)aluminum as cohost materials

Young Gu Lee, Ho-Nyeon Lee, Sung Kee Kang, Tae Sik Oh, Soonil Lee, and Ken Ha Koh

Appl. Phys. Lett. 89, 183515 (2006); http://dx.doi.org/10.1063/1.2374811 (3 pages) | Cited 12 times

Online Publication Date: 2 November 2006

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The authors fabricated red organic light-emitting devices using DCJTB as red dopant, and blue-emitting MADN and green-emitting Alq3 as cohost materials for emission layers. The luminance efficiency of 2% DCJTB-doped Alq3(20%)/MADN(80%) device was 5.42 cd/A at 20 mA/cm2, while that of equivalently doped Alq3 single-host device was 1.79 cd/A, and remained over 5.2 cd/A up to 200 mA/cm2. At the benchmark luminance of 7680 cd/m2, the power efficiency of DCJTB-doped Alq3/MADN device was 4.1 times better than that of Alq3 single-host device. Moreover, the half-decay lifetime of DCJTB-doped Alq3/MADN device measured at an initial luminance of 1000 cd/m2 was 14 000 h.
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85.60.Jb Light-emitting devices

Low-operating-voltage pentacene field-effect transistor with a high-dielectric-constant polymeric gate dielectric

Se Hyun Kim, Sang Yoon Yang, Kwonwoo Shin, Hayoung Jeon, Jong Won Lee, Ki Pyo Hong, and Chan Eon Park

Appl. Phys. Lett. 89, 183516 (2006); http://dx.doi.org/10.1063/1.2374864 (3 pages) | Cited 29 times

Online Publication Date: 2 November 2006

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Low-operating-voltage organic field-effect transistor has been realized by using the cross-linked cyanoethylated poly(vinyl alcohol) (CR-V) as a gate dielectric. The cross-linked CR-V dielectric was found to have a high dielectric constant of 12.6 and good insulating properties, resulting in a high capacitance (92.9 nF/cm2 at 20 Hz) for a dielectric thickness of 120 nm. A pentacene field-effect transistor fabricated with the cross-linked CR-V dielectric was found to exhibit a high carrier mobility (0.62 cm2/V s), a small subthreshold swing (185 mV/decade), and little hysteresis at low operating voltages ( ⩽ −3 V).
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85.30.Tv Field effect devices

Prompt gamma measurements for locating the dose falloff region in the proton therapy

Chul-Hee Min, Chan Hyeong Kim, Min-Young Youn, and Jong-Won Kim

Appl. Phys. Lett. 89, 183517 (2006); http://dx.doi.org/10.1063/1.2378561 (3 pages) | Cited 26 times

Online Publication Date: 2 November 2006

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The location of the distal falloff in the proton therapy is an important but often uncertain parameter as different tissue elements are traversed by the beam. A multilayered collimator system has been constructed as a practical means to locate the dose ends by measuring prompt gammas. The collimator is designed to moderate and capture fast neutrons and to prevent unwanted gammas from reaching the scintillation detector. The system has been studied using Monte Carlo technique and has been tested in the beam energy range of 100–200 MeV. Measurements clearly indicated correlations between the gamma distributions and the distal falloff regions.
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87.53.Bn Dosimetry/exposure assessment
87.56.J- Collimation
29.40.Mc Scintillation detectors
87.55.K- Monte Carlo methods

Hot-carrier effects in p-channel polycrystalline silicon thin film transistors

L. Mariucci, A. Valletta, P. Gaucci, G. Fortunato, and F. Templier

Appl. Phys. Lett. 89, 183518 (2006); http://dx.doi.org/10.1063/1.2378587 (3 pages) | Cited 2 times

Online Publication Date: 2 November 2006

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The effects of hot carriers on the electrical characteristics of polycrystalline silicon p-channel thin film transistors have been analyzed, combining experimental data and numerical simulations. The transfer characteristics showed minor variations upon application of prolonged bias stress, while the output characteristics presented a reduction of kink effect. These results have been explained by using a self-consistent model based on the trapping of injected hot electrons. The authors’ charge injection model provided a precise evaluation of the extension of the trapped charge regions, at both front and back interfaces. By using such trapped charge distributions, it was possible to reproduce the output characteristics variations as well as the minor on-current increase observed in the transfer characteristics after bias stress.
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85.30.Tv Field effect devices

Voltage-controlled multicolor emitting devices

Fuzhi Wang, Ping Wang, Xing Fan, Xiangnan Dang, Changgua Zhen, Dechun Zou, Eun Hwa Kim, Do Nam Lee, and Byeong Hyo Kim

Appl. Phys. Lett. 89, 183519 (2006); http://dx.doi.org/10.1063/1.2382747 (3 pages) | Cited 4 times

Online Publication Date: 2 November 2006

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Voltage-controlled multicolor emitting devices were fabricated by combining an organic light-emitting diode and a solid-state electrochemiluminescent device. Though the device has a simple-stacking structure with Ru(II) complex, tris(8-hydroxyquinolinato) aluminum, 4,4′-bis(2,2′-diphenylvinyl)-1,1′-biphenyl, and N,N′-bis(naphthalen-1-yl)-N,N′-bis(phenyl)-benzidine as basic materials, it is able to stably emit different colors, from pure green to pure red or from pure blue to pure red, under different driving biases. Its luminance can reach up to 1836 cd/m2 with current efficiency reaching 1.84 cd/A. The Ru(II) complex is considered to play a dominant role in this kind of device due to its unique reversible redox property.
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85.60.Jb Light-emitting devices

Cotunneling current in Si single-electron transistor based on multiple islands

Kensaku Ohkura, Tetsuya Kitade, and Anri Nakajima

Appl. Phys. Lett. 89, 183520 (2006); http://dx.doi.org/10.1063/1.2384802 (3 pages) | Cited 3 times

Online Publication Date: 2 November 2006

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The authors fabricated highly doped Si single-electron transistors (SETs) with three islands. The valley current of the obtained Coulomb oscillation was systematically investigated in comparison with the cotunneling theory. The temperature dependence of the valley current was well described by the inelastic cotunneling theory above 40 K in the low drain voltage region. Since the inelastic cotunneling current was confirmed to be dominant in the high temperature region and is exponentially suppressed by multiplexing islands, SETs with multiple islands are promising for the practical application such as reliable circuit operations.
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85.35.Gv Single electron devices

Nondestructive diagnostics of high-κ dielectrics for advanced electronic devices

Claudia Dallera, Francesca Fracassi, Lucio Braicovich, Giovanna Scarel, Claudia Wiemer, Marco Fanciulli, Giuseppe Pavia, and Bruce C. C. Cowie

Appl. Phys. Lett. 89, 183521 (2006); http://dx.doi.org/10.1063/1.2374843 (3 pages) | Cited 6 times

Online Publication Date: 3 November 2006

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The authors present novel results on the interface between silicon and the high-κ oxides Al2O3 and HfO2 grown by atomic layer deposition. The determination of the thickness of the interfacial layer between oxide and Si(100) is crucial to the evaluation of the performances of devices based on high-κ dielectrics. They find through hard x-ray photoemission spectroscopy (HaXPES) that no interfacial layer forms between Al2O3 and Si(100) whereas almost one monolayer forms between HfO2 and Si(100). HaXPES does not involve any destructive procedure nor any sample preparation. High-energy photoemission could therefore be widely employed for the characterization of real devices.
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77.55.-g Dielectric thin films
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
79.60.Jv Interfaces; heterostructures; nanostructures
68.35.Fx Diffusion; interface formation

Effects of gate bias on hot-carrier reliability in drain extended metal-oxide-semiconductor transistors

K. M. Wu, J. F. Chen, Y. K. Su, J. R. Lee, K. W. Lin, J. R. Shih, and S. L. Hsu

Appl. Phys. Lett. 89, 183522 (2006); http://dx.doi.org/10.1063/1.2374881 (3 pages) | Cited 8 times

Online Publication Date: 3 November 2006

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The effect of gate voltage on hot-carrier induced degradation in drain extended high-voltage metal-oxide-semiconductor (MOS) transistors with thick gate oxide (100 nm) structure is presented. Different from the conventional low-voltage n-type MOS transistors, under a fixed drain voltage, devices stressed at a higher Vgs result in a greater maximum transconductance and on-resistance degradation. Under higher Vgs, the increase in channel hot-carrier injection is responsible for the greater Gm,max degradation. On the other hand, Kirk effect induced increase in drain avalanche hot carriers near the drain as well as higher electric field in the channel is responsible for the greater Ron degradation.
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85.30.Tv Field effect devices

Controlled gate surface processing of AlGaN/GaN high electron mobility transistors

Dennis E. Walker, Robert C. Fitch, James K. Gillespie, Gregg H. Jessen, Paul D. Cassity, Joseph R. Breedlove, and Leonard J. Brillson

Appl. Phys. Lett. 89, 183523 (2006); http://dx.doi.org/10.1063/1.2378559 (3 pages) | Cited 3 times

Online Publication Date: 3 November 2006

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The authors have used ultrahigh vacuum surface science techniques combined with gate mask fabrication and processing to demonstrate improvements in the unity gain cutoff frequency response fT of AlGaN/GaN high electron mobility transistors compared to standard processing. In situ annealing, nitrogen ion sputtering and annealing, and Ga reflux plus annealing all displayed increased fT response on average. In situ depth-resolved cathodoluminescence spectroscopy of the AlGaN/GaN interface region reveals changes in GaN near-band edge, 2.2 eV, and 2.9 eV native defect emissions consistent with the average device performance between process steps and between devices with the same treatment on the same wafer.
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85.30.Tv Field effect devices
81.65.Ps Polishing, grinding, surface finishing
85.40.Hp Lithography, masks and pattern transfer

Experimental evaluation of impact ionization coefficients in AlxGa1−xN based avalanche photodiodes

Turgut Tut, Mutlu Gokkavas, Bayram Butun, Serkan Butun, Erkin Ulker, and Ekmel Ozbay

Appl. Phys. Lett. 89, 183524 (2006); http://dx.doi.org/10.1063/1.2385216 (3 pages) | Cited 13 times

Online Publication Date: 3 November 2006

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The authors report on the metal-organic chemical vapor deposition growth, fabrication, and characterization of high performance solar-blind avalanche photodetectors and the experimental evaluation of the impact ionization coefficients that are obtained from the photomultiplication data. A Schottky barrier, suitable for back and front illuminations, is used to determine the impact ionization coefficients of electrons and holes in an AlGaN based avalanche photodiode.
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85.60.Dw Photodiodes; phototransistors; photoresistors
85.60.Gz Photodetectors (including infrared and CCD detectors)
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