International Conference on Physics.SPb/2025

Capacitance studies of solar cells based on nanostructured “black” silicon with a passivating $n$-GaP layer

O. P. Mikhaylov^a, A. I. Baranov^a, A. A. Maksimova^ab, A. V. Uvarov^a, E. A. Vyacheslavova^a, A. S. Gudovskikh<sup>ab

a</sup> Alferov Federal State Budgetary Institution of Higher Education and Science Saint Petersburg National Research Academic University of the Russian Academy of Sciences, 194021 St. Petersburg, Russia
^b Saint Petersburg Electrotechnical University "LETI", 197376 St. Petersburg, Russia

Abstract: The study investigated heterostructure solar cells based on $p$-Si substrates doped with B, featuring a $b$-Si surface created by dry etching. The $n$-layer consisted of a thin film of wide- bandgap GaP grown by plasma-assisted atomic layer deposition. It was demonstrated that irradiation with a 1 MeV electron beam at a fluence of 5 $\cdot$ 10$^{14}$ cm$^{-2}$ reduced the short-circuit current density from 26.3 to 12.2 mA/cm$^2$, and at 1 $\cdot$ 10$^{15}$ cm$^{-2}$, it further decreased to 2.8 mA/cm$^2$. According to quantum efficiency spectra and deep-level transient spectroscopy data, no significant degradation of the bulk silicon properties was observed. However, after irradiation, a kink appeared in the current-voltage characteristics, indicating the presence of a parasitic barrier in the structure. This barrier is attributed to the degradation of the metallic contact to $n$-GaP due to irradiation-induced damage.

Received: 06.05.2025
Revised: 30.06.2025
Accepted: 09.07.2025

DOI: 10.61011/FTP.2025.04.61254.8113