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CuInSe2 surfaces can be cleaned by bombardment with Ar ions at glancing incidence and with energies up to 1.5 keV without change in composition. At near-normal incidence a slight depletion of Cu is observed. The surface crystallinity can be partially restored by annealing to ∼550 °C, without preferential evaporation of an element. On Ar+-cleaned and annealed surfaces, single-crystal low-energy electron diffraction patterns of CuInSe2 have been produced for the first time.

A self-consistent two-carrier numerical model for steady-state current flow in n-semi-insulating-n InP structures allows the treatment of avalanche breakdown in addition to trap filling. Band-to-band impact ionization is included as a source term in the continuity equations. Carrier diffusion, nonlinear velocity field characteristics, and Shockley-Read-Hall recombination through the traps are also included, and the effects of each on the field and trapped carrier distributions are calculated. (The progress of trap filling predicted by the traditional drift-only theory is also calculated.) With impact ionization, hole accumulation near the cathode redistributes the space charge and contributes to positive feedback for avalanche breakdown. The model predictions are consistent with experimentally observed catastrophic breakdown and allow the development of design guidelines for avoiding device failure.

Quantum wires ≊300–400 Å wide were fabricated by holographic photolithography from a wafer having a single 100 Å InGaAs quantum well. The wires were then recoated with InP using atmospheric pressure organometallic vapor phase epitaxy, which resulted in a planar surface. A high-resolution scanning electron microscope showed little deterioration of the wires due to recoating. At moderate intensities ≊10 W/cm2, photoluminescence (PL) studies showed a small shift in energy (≊6 meV) and a slight line narrowing consistent with a one-dimensional structure. The quantum efficiency of the wires was comparable to the control wafer—above that expected from the fill factor of 17%. Some evidence of states below the energy gap is seen at low PL excitation, but these appear to saturate at higher excitations.