Exceeding the solar cell Shockley-Queisser limit via thermal up-conversion of low-energy photons

OPTICS COMMUNICATIONS

卷:314

Article

Boriskina, Svetlana V.¹  Chen, Gang¹ 

[1] MIT, Dept Mech Engn, Cambridge, MA 02139 USA

关键词: Photovoltaics;    Thermophotovoltaics;    Solar energy conversion;    Up-conversion;    Frequency-selective surfaces;    Angularly-selective surfaces;   

DOI  :  10.1016/j.optcom.2013.10.042

来源: Elsevier

【 摘 要 】

Maximum efficiency of ideal single-junction photovoltaic (PV) cells is limited to 33% (for 1 sun illumination) by intrinsic losses such as band edge thermalization, radiative recombination, and inability to absorb below-bandgap photons. This intrinsic thermodynamic limit, named after Shockley and Queisser (S-Q, can be exceeded by utilizing low-energy photons either via their electronic up-conversion or via the thermophotovoltaic (TPV) conversion process. However, electronic up-conversion systems have extremely low efficiencies, and practical temperature considerations limit the operation of TPV converters to the narrow-gap PV cells. Here we develop a conceptual design of a hybrid TPV platform, which exploits thermal up-conversion of low-energy photons and is compatible with conventional silicon PV cells by using spectral and directional selectivity of the up-converter. The hybrid platform offers sunlight-to-electricity conversion efficiency exceeding that imposed by the S-Q limit on the corresponding PV cells across a broad range of bandgap energies, under low optical concentration (1-300 suns), operating temperatures in the range 900-1700 K, and in simple flat panel designs. We demonstrate maximum conversion efficiency of 73% under illumination by non-concentrated sunlight. A detailed analysis of non-ideal hybrid platforms that allows for up to 15% of absorption/re-emission losses yields limiting efficiency value of 45% for Si PV cells. (C) 2013 Elsevier B.V. All rights reserved.

【 授权许可】

Free