Cu_2ZnSnS4(CZTS) films are successfully prepared by co-electrodeposition in aqueous ionic solution and sulfurized in elemental sulfur vapor ambient at 400 C for 30 min using nitrogen as the protective gas.It is found that the CZTS film synthesized at Cu/(Zn+Sn)=0.71 has a kesterite structure,a bandgap of about 1.51 eV,and an absorption coefficient of the order of 10 4 cm 1.This indicates that the co-electrodeposition method with aqueous ionic solution is a viable process for the growth of CZTS films for application in photovoltaic devices.
We present a numerical gas phase reaction model for hydrogenated microcrystalline silicon(μc-Si:H) films from SiH4 and H2 gas mixtures with plasma enhanced chemical vapor deposition(PECVD).Under the typical μc-Si:H deposition conditions,the concentrations of the species in the plasma are calculated and the effects of silane fraction(SF=[SiH4]/[H2+SiH4]) are investigated.The results show that SiH3 is the key precursor for μc-Si:H films growth,and other neutral radicals,such as Si2H5,Si2H4 and SiH2,may play some roles in the film deposition.With the silane fraction increasing,the precursor concentration increases,but H atom concentration decreases rapidly,which results in the lower H/SiH3 ratio.
Microcrystalline silicon (μc-Si:H) thin films with and without boron doping are deposited using the radio-frequency plasma-enhanced chemical vapour deposition method.The surface roughness evolutions of the silicon thin films are investigated using ex situ spectroscopic ellipsometry and an atomic force microscope.It is shown that the growth exponent β and the roughness exponent α are about 0.369 and 0.95 for the undoped thin film,respectively.Whereas,for the boron-doped μc-Si:H thin film,β increases to 0.534 and α decreases to 0.46 due to the shadowing effect.
