P+aSixC1-x: H/i-aSi:H/n+aSi1-xGex:H graded band gap single junction solar cell with composition graded amorphous silicon carbon alloy as window layer

Abstract

The work explores the conduct of composition graded amorphous silicon carbon alloy (aSixC1-x: H) as window layer on graded band gap amorphous silicon (p+aSixC1-x: H/i-aSi:H/n+aSi1-xGe x:H) solar cells, for the first time. The working principle of the proposed structure is interpreted with the aid of energy band diagram. Experimentally validated parameters were adopted for the simulation of the proposed structure. It is observed that the proposed structure is efficient in delivering conversion efficiency (η) of 15.39% at 300 K on reducing its window layer thickness to 5 nm, which is commensurate to other announced amorphous silicon solar cells. The momentous cutback in thickness of one of the active layer leads to lesser material demand and diminishes the overall manufacturing cost. Further, the effect of variation in temperature on the proposed structure has been evaluated and observed that the performance remain almost unaltered. Furthermore, the proposed solar cell structure is compared with our previous work and state of art of single junction amorphous silicon solar cell structures.