Assessing doping inhomogeneities in GaAs crystal via simulations of lateral photovoltage scanning method

We performed a numerical feasibility study of the application of the lateral photovoltage scanning (LPS) method to detect doping inhomogeneities (striations) in GaAs. Those striations follow the shape of the crystallization front, enabling its visualization. The obtained results allow direct validation of simulated temperature distributions in GaAs crystals. Our simulations revealed that realistic laser powers lead to LPS signals on the order of nanovolts. The actually used LPS measurement setup detects voltages at microvolt scale. So in order to build practical setups, one needs to either use better voltage detection devices or improve the method itself.