@inproceedings{84eb50e0ff3146679a84a88bea4851a6,
title = "1.7eV Al0.2Ga0.8As solar cells epitaxially grown on silicon by SSMBE using a superlattice and dislocation filters",
abstract = "Lattice-mismatched 1.7eV Al0.2Ga0.8As photovoltaic solar cells have been monolithically grown on Si substrates using Solid Source Molecular Beam Epitaxy (SSMBE). As a consequence of the 4%-lattice-mismatch, threading dislocations (TDs) nucleate at the interface between the Si substrate and III-V epilayers and propagate to the active regions of the cell. There they act as recombination centers and degrade the performances of the cell. In our case, direct AlAs/GaAs superlattice growth coupled with InAlAs/AlAs strained layer superlattice (SLS) dislocation filter layers (DFLSs) have been used to reduce the TD density from 1×109cm-2 to 1(±0.2)×107cm-2. Lattice-matched Al0.2Ga0.8As cells have also been grown on GaAs as a reference. The best cell grown on silicon exhibits a Voc of 964mV, compared with a Voc of 1128mV on GaAs. Fill factors of respectively 77.6% and 80.2% have been calculated. Due to the lack of an anti-reflection coating and the non-optimized architecture of the devices, relatively low Jsc have been measured: 7.30mA.cm-2 on Si and 6.74mA.cm-2 on GaAs. The difference in short-circuit currents is believed to be caused by a difference of thickness between the samples due to discrepancies in the calibration of the MBE prior to each growth. The bandgap-voltage offset of the cells, defined as Eg/q-Voc, is relatively high on both substrates with 736mV measured on Si versus 572mV on GaAs. The non-negligible TD density partly explains this result on Si. On GaAs, non-ideal growth conditions are possibly responsible for these suboptimal performances.",
keywords = "AlGaAs solar cell, Dislocation filter, III-V on silicon, MBE, Superlattice, Threading dislocation density",
author = "Arthur Onno and Jiang Wu and Qi Jiang and Siming Chen and Mingchu Tang and Yurii Maidaniuk and Mourad Benamara and Mazur, {Yuriy I.} and Salamo, {Gregory J.} and Harder, {Nils Peter} and Lars Oberbeck and Huiyin Liu",
note = "Publisher Copyright: {\textcopyright} 2016 SPIE.; Physics, Simulation, and Photonic Engineering of Photovoltaic Devices V ; Conference date: 15-02-2016 Through 17-02-2016",
year = "2016",
doi = "10.1117/12.2208950",
language = "English (US)",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
editor = "Alexandre Freundlich and Laurent Lombez and Masakazu Sugiyama",
booktitle = "Physics, Simulation, and Photonic Engineering of Photovoltaic Devices V",
}