Surface passivation is a widely used technique to reduce the recombination losses at the semiconductor surface. The passivating layer performance can be mainly characterized by two parameters: The fixed charge density (Q(ox)) and the interface trap density (D-it) which can be extracted from Capacitance-Voltage measurements (CV). In this paper, simulations of High-Frequency Capacitance-Voltage (HF-CV) curves were developed using simulated passivation parameters in order to examine the reliability of measured results. The D-it was modelled by two different sets of functions: First, the sum of Gaussian functions representing different dangling bond types and exponential tails for strained bonds. Second, a simpler U-shape model represented by the sum of exponential tails and a constant value function was employed. These simulations were validated using experimental measurements of a referenc...

This study presents for the first time the spectral impact on the performance of different photovoltaic (PV) technologies in Lima, Peru. We experimentally monitored the spectral distributions over one year (March 2019–February 2020). The average photon energy (APE) is calculated as a representative parameter to evaluate the spectral distributions. The spectral mismatch factor (MM) enables an estimation of the spectral gains of distinct PV technologies: amorphous silicon (a-Si), perovskite, cadmium telluride (CdTe), multicrystalline silicon (multi-Si), monocrystalline silicon (mono-Si) and copper indium gallium selenide with two distinct band-gaps (CIGS-1 and CIGS-2). We found that the annual APE has a value of 1.923 eV, indicating that the spectrum is shifted to shorter wavelengths. In contrast to studies performed in other locations, the spectral distribution shows relatively small mo...

We demonstrate that the modulated surface photovoltage spectroscopy (modulated SPS) technique can be applied to investigate interface states in the bandgap, i.e. interface passivation, of crystalline silicon coated with a downshift layer such as hydrogenated aluminum nitride with embedded terbium ions by suppressing straylight with a cut-off filter. Different hydrogen contents influence the surface photovoltage spectra at photon energies below the bandgap of crystalline silicon. Modulated SPS reveals that at higher hydrogen content there is a lower signal and, thus, a lower density of surface defect states. Our experiments show that modulated SPS can become a powerful tool for characterizing defect states at interfaces which cannot be easily studied by other methods. © 2021 Published under licence by IOP Publishing Ltd.