Abstract
The optical properties of porous GaAs formed electrochemically on n- and p-type GaAs in HCl electrolyte are reported. The porous structure comprises GaAs crystallites ranging in size from micrometers to nanometers and under certain chemical conditions other transparent crystallites form. Photoluminescence (PL) measurements at 295 K reveal an ''infrared'' PL at similar to 840 nm and a ''green'' PL at similar to 540 nm that could easily be seen by the naked eye in some samples. The infrared and green PL wavelength and intensity varied from sample to sample consistent with an assignment to quantum confinement effects in GaAs micro- and nanocrystallites, respectively. Raman scattering measurements identified the transparent crystallites as As2O3. Ga2O3 was also detected in some samples.