AlGaAs top solar cell for mechanical attachment in a multi-junction tandem concentrator solar cell stack

A review of concentrator silicon solar cells

“…16, and we also called them silicon based multi-junction cell in this work. Gee et al made a two-junction GaAs/Si tandem cell with the efficiency of 31% under 347 suns [119], DiNetta et al made a two-junction Al x Ga 1-x As/Si tandem cell with the efficiency of 29.2% under 100 suns [120]. Green et al built a power tower concentrating system, they used a bandpass filter to split the concentrated sunlight into two parts, a three-junction GaInP/ GaInAs/Ge cell was used to absorb the reflected light, a Si back contact cell made by Sunpower company was used to absorb the transmitted light, the concentration ratio was 365 suns and the total efficiency reached 40.4%, which was the highest efficiency of the concentration systems of this kind [121].…”

Design, fabrication, and analysis of transparent silicon solar cells for multi‐junction assemblies

“…However, the GaAs substrate has a lower band gap than the active AlGaAs device, which causes absorption of sub‐band gap photons that are meant for the lower band gap junction. To mitigate this parasitic absorption, we employed techniques such as wafer thinning . In 2009, a device that utilizes a transparent silicon solar cell in a five‐junction assembly reported a sum of solar cell efficiencies of 42.7%, with the silicon contributing 5.4% at 8.7 suns .…”