화학적 용액성장법에 의한 ZnS 박막의 제조 시 ammonia 및 Na2EDTA의 영향

Abstract

ZnS thin films were prepared on glass substrate by using chemical bath deposition method. The influence of ammonia (<TEX>$NH_4OH$</TEX>) and <TEX>$Na_2EDTA$</TEX> (<TEX>$Na_2C_{10}H_{16}N_2O_8$</TEX>) as complexing agents on structural and optical properties of ZnS thin films were investigated. Zinc acetate dihydrate (<TEX>$Zn(CH_3COO)_2{\cdot}2H_2O$</TEX>) and thiourea (<TEX>$H_2NCSNH_2$</TEX>) were used as a starting materials and distilled water was used as a solvent. All ZnS thin films, regardless of a kind of complexing agents, had the hexagonal structure (<TEX>${\alpha}$</TEX>-ZnS) and had a preferred <101> orientation. ZnS thin films, with 4 M ammonia and with 4 M ammonia and 0.1 M <TEX>$Na_2EDTA$</TEX>, had the highest <101> peak intensity. In addition, their average particle size are 280 nm and 220 nm, respectively. The average optical transmittances of all films were higher than 60% in the visible range. The optical direct band gap values of films were about 3.6~3.8 eV.