Improved photoresponse of InAs/GaAs quantum dot infrared photodetectors by using GaAs_1−xSb_x strain reducing layer

Chia-Tze Huang, Yu-Cheng Chen, and Si-Chen Lee

The authors investigated the effect of a GaAs_1−xSb_x strain reducing layer on the performance of InAs/GaAs quantum-dot infrared photodetectors (QDIPs). The authors show that by increasing the Sb concentration to 20%, the resulting type-II structure provided a higher barrier for enhancing electron confinement, thus improving the spectral responsivity and operation temperature.

Appl. Phys. Lett. 100, 043512 (2012)

Effect of an electron blocking layer on the piezoelectric field in InGaN/GaN multiple quantum well light-emitting diodes

Dong-Yul Lee, Sang-Heon Han, Dong-Ju Lee, Jeong Wook Lee, Dong-Joon Kim, Young Sun Kim, and Sung-Tae Kim

The authors report the effect of an electron blocking layer (EBL) on the piezoelectric field in InGaN/GaN multiple quantum well light-emitting diodes (LEDs). LEDs with a p-AlGaN EBL exhibited reduced blueshift and a sublinear increase of full width at half maximum in their EL spectra at low current densities.

Appl. Phys. Lett. 100, 041119 (2012)

Giant electro-mechanical energy conversion in [011] cut ferroelectric single crystals

Wen D. Dong, Peter Finkel, Ahmed Amin, and Christopher S. Lynch

The authors demonstrate giant electro-mechanical energy conversion under a ferroelectric/ferroelectric phase transformation in [011] cut and poled lead titanate-based relaxor perovskite morphotropic single crystals. They found that under mechanical pre-stress, a relatively small oscillatory stress drives the material reversibly between rhombohedral and orthorhombic phases with a remarkably high polarization and strain jump induced at zero bias electric field and room temperature. The measured electrical output per cycle is more than an order of magnitude larger than that reported for linear piezoelectric materials.

Appl. Phys. Lett. 100, 042903 (2012)

Model of random telegraph noise in gate-induced drain leakage current of high-k gate dielectric metal-oxide-semiconductor field-effect transistors

Ju-Wan Lee and Jong-Ho Lee

The authors propose a model to explain the generation mechanism of appreciable random telegraph noise (RTN) in the gate-induced drain leakage (GIDL) current of the high-k gate dielectric MOSFETs and explain uncorrelated RTNs in the GIDL and the gate ET currents.

Appl. Phys. Lett. 100, 033501 (2012)

Advantages of blue InGaN light-emitting diodes with InGaN-AlGaN-InGaN barriers

Yen-Kuang Kuo, Tsun-Hsin Wang, and Jih-Yuan Chang

The authors demonstrate that the performance of the blue InGaN LEDs is markedly improved when the GaN barriers are replaced by InGaN-AlGaN-InGaN barriers due to the appropriately modified energy band diagrams, high carrier injection efficiency, uniform distribution of carriers in the QWs, high radiative recombination rate in the active region, and small efficiency droop.

Appl. Phys. Lett. 100, 031112 (2012)