Current-Matched III–V/Si Epitaxial Tandem Solar Cells with 25.0% Efficiency

Cell Reports Physical Science

Ryan D. Hool¹  Erik D. Ratta²  Mijung Kim³  Minjoo L. Lee³  Zhengshan J. Yu³  Brian D. Li⁴  Shizhao Fan⁴  William Weigand⁴  Zachary C. Holman⁴  Yukun Sun⁵  Pankul Dhingra⁵ 

[1] Corresponding author;Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA;Holonyak Micro and Nanotechnology Laboratory, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA;Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA;School of Electrical, Computer, and Energy Engineering, Arizona State University, Tempe, AZ 85287, USA;

关键词: Epitaxial III-V/Si integration;    tandem;    GaAsP;    red response;    current match;   

DOI  :  

来源: DOAJ

【 摘 要 】

Summary: III–V/Si epitaxial tandems with a 1.7-eV GaAsP top cell promise stable power conversion efficiencies above the fundamental limit of Si single-junction cells. However, III–V/Si epitaxial tandems have suffered from limited minority carrier diffusion length in the top cell, leading to reduced short-circuit current densities (JSC) and efficiencies. While conventional wisdom dictates that dislocation density in III–V/Si tandems must be reduced to boost efficiency, here, we show that heterointerface design and growth sequence also play critical roles in reducing recombination losses. Our improved GaAsP cells make use of a wide-band gap AlGaAsP electron-blocking layer that forms a pristine interface with GaAsP, resulting in a 10%–20% (absolute) boost in quantum efficiency over previous work in the critical red wavelength range (600–725 nm), despite similar dislocation density. Combining the improved top cell carrier collection with Si backside texturing, we obtain 25.0% efficient GaAsP/Si tandem cells with a closely matched JSC of 18.8 mA/cm2.

【 授权许可】

Unknown