Modeling and simulation of layer-transferred thin silicon solar cell with quasi monocrystalline porous silicon as active layer

摘要

Solar cells using quasi monocrystalline porous silicon (QMPS) as an active device layer could fulfill the aim of low cost solar power by dispensing with the high quality, expensive crystalline or epitaxial material and providing an opportunity to obtain higher efficiency by enhanced light absorption by the voids of this layer. This paper is intended to demonstrate through estimation of cell parameters, why QMPS layer could become a suitable alternative to existing technologies for thin silicon solar cell. For the computation of cell parameters, modeling of transport parameters for the QMPS layer has been first performed. Dependence of the parameters of cells fabricated directly on QMPS layer formed by annealing at different annealing temperature and with different initial porosities is then studied. The effects of series and shunt resistance on the cell performance have also been investigated. The important role of minority carrier density at the interface states at silicon-void interface on the cell parameters, particularly in lowering the open circuit voltage (V_(oc)) to less than 400 mV has been presented. The improvement of the cell performance depends on the controlling of the passivation of these interface states. It is concluded that it is possible to achieve efficiency of about 15% with V_(oc) ～ 500 mV from active QMPS layer solar cell provided void-silicon interface states are properly passivated.