Fabrication of low cost nano-grass n-type C-Si solar cell with sol–gel Al2O3 passivation

Abstract

Silicon nano-grass Solar cell has the advantage of enhancing efficiency with cost effective method. Highly ordered silicon nano-grass is formed by chemical etching process. During this chemical etching unwanted nanograss is formed on both side of the wafer, resulting considerable transmission loss from rear side. This results in ultimate reduction of efficiency. The detrimental effect of nano-grass formation on both side of the wafer is briefly demonstrated here by simulation methods. Adopting the idea by simulation method this paper has reported silicon front sided nano-grass n-type c-Si solar cell by spin on diffusion source and rapid thermal annealing. The sheet resistance of the nano-grass silicon wafer is varied with respect to different spin-on diffusion profile. Later front surface has been passivated by sol–gel Al2O3 passivation. Eventually all the spin doped silicon nano-grass solar cell with sol–gel Al2O3 passivation provides a very promising route of cost effective high efficiency silicon solar cell technology. Broadband reflection between 300 and 1100 nm wavelengths has been suppressed to 2% for nano-grass Solar cell and maximum efficiency of 16.57% is achieved.