A novel photodetector based upon annealed low temperature molecular beam epitaxy GaAs capable of detecting wavelengths out to 1.5 mm has been developed. The device utilizes a photoconductive detector with a high photo-generated carrier lifetime to transit time ratio in order to achieve a high internal gain. The sensitivity to illumination with photons of sub-bandgap energies is achieved due to ...

We model the TPA-induced free carrier absorption effect in silicon Raman amplifiers and quantify the conditions under which net gain may be obtained. The achievable Raman gain strongly depends on the free carrier lifetime, propagation loss, and on the effective Raman gain coefficient, through pump-induced broadening.

We have determined the depth of ion implant damage in semiconductor materials by nonlinear optical measurements. The carrier lifetime in ion-implanted mesas was measured by the pump-probe technique, and the carrier diffusion coefficient in unetched material was measured by degenerate four-wave mixing. An effective depth of damage within which the carriers experience fast recombination is then d...

Surface texturing is a more permanent and effective solution to eliminate reflections compared with antireflection coatings in optical devices. In this study texturing was performed using a reactive ion etching technique, reflectance was measured and the resultant damage on the surfaces was monitored through the minority carrier lifetime measurements. High minority carrier lifetime is an indica...

Organic-inorganic hybrid perovskites are attracting intense research effort due to their impressive performance in solar cells. While the carrier transport parameters such as mobility and bulk carrier lifetime shows sufficient characteristics, the surface recombination, which can have major impact on the solar cell performance, has not been studied. Here we measure surface recombination dynamic...

Transient photoconductance decay (PCD) in ingots or wafers has been numerically simulated by a finite-element method (FEM). We examined two types of light sources for carrier injection in transient PCD measurements. Large discrepancies between the widely used asymptotic approximation and the FEM simulations of wafers were seen, and an empirical fitting of the FEM results suggests that the effec...