Performance evaluation of thin film GaSb thermophotovoltaic cells

Economical converters are the key component for the industrial applications of thermophotovoltaic technology. In this work thin film GaSb cells are demonstrated for broadband thermophotovoltaic energy conversion. It is shown that n-on-p configuration is a superior choice for thin film cell due to its larger accessible efficiency. Under the illumination of unshaped blackbody spectrum, the matched spectrum temperature for GaSb thin film cells should be in the range of 2000∼2600 K, With those matched spectra, the optimal GaSb thin film can achieve the efficiency up to 8% or so with VOC = 0.55 V, FF = 0.64, JSC = 44 A cm−2, thus showing the power density output up to 15 W cm−2 while only having the active layer thickness 4.5 μm or so. These results are well preserved for SF no more than 104 cm s−1. With increasing spectrum temperature, a phenomenological model has also been formulated to analytically predict the optimal cell structure at a given spectrum illumination. This work has thus established the fundamental guidelines to develop GaSb thin film cells or subcells for economical thermophotovoltaic energy conversion.