GaN intermediate band solar cells with Mn-doped absorption layer

Abstract

The effect of Mn concentration on the optical properties of Mn-doped layers grown by metalorganic vapor phase epitaxy is investigated. The Mn-doped GaN layers exhibite a typical transmittance spectrum with a distinct dip around 820 nm which is attributed to the transition of electrons between the edge of valence band and the Mn-related states within the bandgap. In addition, electroluminescence (EL) spectra obtained from the bipolar devices with Mn-doped GaN active layer also show that considerable Mn-related energy states existed in the bandgap. The position of the Mn-related energy states in the GaN is first evaluated via EL spectra. In addition to the absorption of band edge, the Mn-related energy states behaving like an intermediate band cause an additional sub-band gap absorption. Consequently, the fabricated GaN-based solar cells using Mn-doed GaN as the absorption layer exhibit photocurrent higher than the control devices without Mn doping. Under one-sun air mass 1.5 G testing condition, the short-circuit current of the Mn-doed GaN solar cells can be enhanced by a magnitude of 10 times compared with the cells without Mn doping.

Machine-learned impurity level prediction for semiconductors: the example of Cd-based chalcogenides

“…For instance, III-V semiconductors such as GaN, GaP, GaAlP, AlP, BP etc. are interesting materials for photodiodes, solar cells, and in recent times, have been studied for intermediate band photovoltaic applications [64][65][66][67] . A quick screening of impurity atoms that can not only change the equilibrium Fermi level, but also create energy level(s) in the band gap, can be made possible using machine learned models to predict impurity properties.…”

Intermediate band solar cells: Present and future

“…Bulk semiconductors with DLIs have demonstrated the capability of achieving relatively strong below-bandgap photocurrent. 32,46 New candidate materials continue to be proposed and analyzed, [47][48][49][50][51][52][53][54] generally proving below-bandgap absorption, which evidences that the DLI approach is far from exhausted. However, we think that at this moment more profound studies are needed.…”

CVD-Grown Monolayer MoS2 and GaN Thin Film Heterostructure for a Self-Powered and Bidirectional Photodetector with an Extended Active Spectrum

“…This broad sensitivity can be attributed to the heterogeneous absorption characteristics of the heterostructure, as depicted in Figure c, which enables the absorbance spectra in the UV region for bare GaN, in line with its wide band gap characteristics. Notably, Fabry–Perot resonance is discernible in the visible regions due to the epitaxial growth consistent with existing literature . Moreover, the MoS 2 /GaN heterostructure broadens the absorbance spectrum into the visible range.…”