The effects of hydrogenation on electrical and optical properties of Si-doped, and C-doped GaAs have been investigated with Polaron profile, Hall effect measurement at room temperature and photoluminescence (PL) at 15K. The mobilities of electrons and holes and resisvity increase, after hydrogenation whereas carrier concentration decrease both in Si-doped and C-doped GaAs.
In Si-doped GaAs, the maximum intensity peak of PL spectra is shifted towards higher energy(blue-shift) and full width at half maximum(FWHM) is broadend with increasing free electron concentration, but, after hydrogenation this PL emission peak is shifted to the low energy side(red-shift) and FWHM became narrow for all doping levels. At concentration of $2.64\times10^{18}cm{-3}$, Donor-to-acceptor(D-A) transition at 1.486eV is observed in PL spectra, and the luminescence intensity of this transition is decreased by hydrogenation. At concentration of $1.04\times10^{17}cm^{-3}$, the conduction band-to-acceptor(C-A) transition is newly appeared at 1.491eV after hydrogenation.
With increasing amounts of carbon, the red-shift is occured in C-doped GaAs, after hydrogenation the blue-shift is occured. At highest concentration$(9.0\times10^{19}cm{-3})$, weak peaking at 1.486eV is shown which is due to K non-conserving recombination. The luminescence spectra of the lowest concentration$(1.09\times10^{18}cm^{-3})$ show strong emission peaking by C-A at 1.494eV and very weak peaking at 1.512eV by exiton recombination. The luminescence intensity of exiton reconbination increase after hydrogenation.
