Correct evaluation of ohmic contacts to p-CdTe thin films

Sometimes it is very difficult to characterise the ohmicity of the metal-semiconductor contact using transmission line model (TLM) measurements, particularly for the semiconductor having a high workfunction. The TLM data are insufficient for polycrystalline films because of the presence of the grain boundary potential which scatters the carriers during their flow along the horizontal direction. Thus the measurement needs modifications in order to obtain the precise value of bulk resistivity rho _B ( Omega cm) specific contact rho _c ( Omega /cm²) and end resistance R_E( Omega ). In the Letter a method is prescribed for determining the exact value of rho _B, rho _c and R_E. This method is very simple and can be adopted by laboratories lacking high grade instrumentation.