Abstract: To verify the direct-gap transition of a SiGe multi-quantum well and grope for its application in thermophotovoltaic cells,a high quality SiGe multi-quantum well is grown by our UHV-CVDII system.The absorption measurement of the SiGe multi-quantum well by multiple internal reflection indicates that the extension of the absorption is up to 1450nm and transition probability caused by the quantum effect in the quantum well of strained SiGe thin layer is higher.Consequently,the absorption efficiency of thermophotovoltaic cells will be increased significantly.

Key words: multi-quantum well,  low bandgap,  thermophotovoltaic cells,  UHV-CVD,  blackbody radiation