Theoretical consideration of III–V nanowire/Si triple-junction solar cells

In this paper, we report theoretical consideration and simulation of a proposed III–V nanowire (NW)/Si triple-junction solar cell. The cell consists of two axially connected III–V NW subcells that are grown and electrically integrated on an active Si substrate. The optical properties of the cell are thoroughly analyzed by using the finite-difference time-domain method. It is found that NW subcells with optimized geometry have high absorption throughout their absorption region. Meanwhile, beyond the absorption edge of the top and middle NW subcells, the NWs act as an efficient antireflection coating for the bottom Si subcell due to the formation of an optical cavity within the NW layer. The physics responsible for the enhanced light harvesting process is qualitatively explained through modal analysis. In addition, we have shown that the condition of current matching in a III–V NW/Si multi-junction can be fulfilled by adjusting the diameter of the NWs. In order to study the curren…

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2012-11-26 20:01:23

Source: http://nanochemistry.blogspot.com/2012/11/theoretical-consideration-of-iiiv.html