Luminescence coupling effects on multijunction solar cell external quantum efficiency measurement

• DOI: 10.1002/pip.1215
• Publication Date: 2011-12-02T07:33:58Z
• Authors: Swee Hoe Lim; Jing‐Jing Li; Elizabeth H. Stee...; Yong‐Hang Zhang
• Keywords: 0202 electrical engineering, electronic engineering, information engineering; 02 engineering and technology; 7. Clean energy

ABSTRACTThe effects of luminescence coupling on the external quantum efficiency (EQE) measurement of an InGaP/InGaAs/Ge triple junction solar cell were investigated. A small signal model was used to study the interaction of the subcells during EQE measurement. It was found that an optical–electrical feedback mechanism results in EQE measurement artifacts. Measurements of luminescence from the InGaP p–n junction are also performed to quantitatively determine the strength of the luminescence coupling. These results offer a more thorough and comprehensive interpretation of EQE measurement results that are needed for the design and accurate performance evaluation of high‐efficiency multijunction solar cells. The effects demonstrated here can also be used to measure the spontaneous emission efficiency of the subcells, which is useful for nondestructive assessment of multijunction solar cell material quality. Copyright © 2011 John Wiley & Sons, Ltd.