**5. Simulation of solar cell**

AMPS 1D beta version (Penn State Univ.) was used to simulate the current voltage characteristics of p-*i*-n junction AlSb solar cells. The physics of solar cell is governed by three equations: Poisson's equation (links free carrier populations, trapped charge populations, and ionized dopant populations to the electrostatic field present in a material system), the continuity equations (keeps track of the conduction band electrons and valence band holes) for free holes and free electrons. AMPS has been used to solve these three coupled nonlinear differential equations subject to appropriate boundary conditions. Following simulation parameters was used for the different layers of films.


*\* N*DG/AG the donor-like or acceptor-like defect density, *W*G the energy width of the Gaussian distribution for the defect states, *τ* carrier lifetime, and *σ* capture cross section of electrons (*σ***e**) or holes (*σ***p**).

Table 2. Parameters of the simulating the IV behavior or p-*i*-n junction solar cells.

Fig. 8. Current-voltage simulation of AlSb p-i-n junction structure in AMPS 1D software.

Fig. 8 shows the current voltage simulation curve of pin junction solar cell - CuSCN/AlSb/ZnO with AlSb as an intrinsic layer. CuSCN was used as a p layer and ZnO as a n layer. The cell was illuminated under one sun at standard AM 1.5 spectrum.

The simulation result shows that the solar cell has the FF of 55.5% and efficiency of 14.41%. The short circuit current for the cell was observed to be 21.7 mA/cm2 and the open circuit voltage was observed to be 1.19 V. AlSb is thus the promising solar cell material for thin film solar cells. The efficiency of the same cell structure could be seen increased up to 19% by doubling the thickness of AlSb layer to 2 micron.
