Structural studies on vacuum evaporated ZnSe/p-Si Schottky diodes

ZnSe/Si heterostructures, fabricated by vacuum evaporation method, are investigated by Rutherford backscattering spectrometry (RBS), X-ray diffraction (XRD), optical, I-V, C-V analysis, high-resolution electron microscopy (HREM) and ab initio quantum mechanics calculations. From the RBS analysis, the composition of the deposited film is found to be nearly stoichiometric. The structural studies show that the orientation of the crystallites in the deposited film is along (1 1 1) direction. Particle size (D), strain (ε) and dislocation density (δ) values are calculated as 40.71 nm, 0.95 x 10-3 lin-2 m-4 and 6.03 x 1015 lin m-2, respectively, while ZnSe/Si interface was locally studied to establish the high interaction between both crystals and it clears that the Si order produce the gradual array in the ZnSe crystallization. The optical band gap value of the deposited films is calculated as 2.61 eV. The ideality factor is evaluated from the I-V measurement and its value is found to be in the range of 2.8-3.01. From the C-V analysis, the built in potential is found to be 0.61 V. The value of effective carrier concentration (N A) and the barrier height are determined as 3.8 x 1011 cm-3 and 1.457 eV, respectively