Work

On the absorption coefficient of GaP1-xNx layers and its potential application for silicon photovoltaics

Year: 2024

Type: article

Abstract: The absorption coefficient and the energy gap of GaP1-xNx layers has been obtained by spectroscopic ellipsometry for samples grown on Si(001) substrates by chemical beam epitaxy with N mole fractions in the range 0 ≤ x ≤ 0.081. The resulting absorption spectra exhibit a direct band-like behavior near the absorption edge. The absorption coefficient values increase with the N content, in the range a ∼ 1-2 × 104 cm−1, which are comparable to those obtained for high efficiency solar cell materials. Furthermore, dependence of the absorption coefficient with increasing N content points out to a strong GaP G-like character of the conduction-band wave function of GaP1-xNx alloys near the Brillouin zone center at k = 0, as predicted by the band anticrossing model. Bandgap energy values obtained by spectroscopic ellipsometry are compared with previous values obtained by photoluminescence measurements on the same samples, observing a shift of about 50-100 meV. Finally, the value of the band anticrossing parameter coupling the N level and the host GaP conduction band has been obtained from the dependence of both, the bandgap and the absorption coefficient, with the N content (2.2 and 3.3 eV respectively).

Source: Materials Science in Semiconductor Processing

DOI: 10.1016/j.mssp.2024.109011

Authors: K. Ben Saddik, M.J. Hernández, M.A. Pampillón, M. Cervera, B.J. García

Institutions: Universidad Autónoma de Madrid, Centro de Micro-Análisis de Materiales

Language: English

Topic: solar cell performance optimization

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,060

Funders: Ministerio de Ciencia, Innovación y Universidades, Ministerio de Ciencia e Innovación