Evidence is presented for phase separation in In0.27Ga0.73N/GaN multiple quantum wells. After annealing for 40 h at a temperature of 950 °C, the absorption threshold at 2.95 eV is replaced by a broad peak at 2.65 eV. This peak is attributed to the formation of In-rich InGaN phases in the active region. X-ray diffraction measurements show a shift in the diffraction peaks toward GaN, consistent with the formation of an In-poor phase. A diffraction peak corresponding to an In-rich phase is also present in the annealed material. Nanoscale In-rich InGaN precipitates are observed by transmission electron microscopy and energy dispersive x-ray chemical analysis.

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Scalable circuits of organic logic and memory are realized using all-additive printing processes. A 3-bit organic complementary decoder is fabricated and used to read and write non-volatile, rewritable ferroelectric memory. The decoder-memory array is patterned by inkjet and gravure printing on flexible plastics. Simulation models for the organic transistors are developed, enabling circuit designs tolerant of the variations in printed devices. We explain the key design rules in fabrication of complex printed circuits and elucidate the performance requirements of materials and devices for reliable organic digital logic.

Enhanced photoanode properties of epitaxial Ti doped α-Fe2O3 (0001) thin films Appl. Phys. Lett. 101, 133908 (2012) Structure and optical band gap of ZnO1−xSx thin films synthesized by chemical spray pyrolysis for application in solar cells J. Appl. Phys. 112, 063708 (2012) Roto-flexoelectric coupling impact on the phase diagrams and pyroelectricity of thin SrTiO3 films J. Appl. Phys. 112, 064111 (2012) Plasmonic effects of ultra-thin Mo films on hydrogenated amorphous Si photovoltaic cells

Interdiffusion of In and Ga is observed in InGaN/GaN multiple quantum wells for annealing temperatures of 1300–1400 °C. Hydrostatic pressures of up to 15 kbar were applied to prevent surface decomposition. In as-grown material, x-ray diffraction spectra show InGaN diffraction peaks up to the fourth order. After annealing at 1400 °C for 15 min, only the zero-order peak is observed, as a result of compositional disordering of the quantum well superlattice. Transmission electron microscopy confirms that the superlattice is completely disordered after annealing at 1400 °C for 15 min.