Influence of Ammonia and Na2EDTA on Properties of Chemical Bath Deposited ZnS Thin Films
화학적 용액성장법에 의한 ZnS 박막의 제조 시 ammonia 및 Na2EDTA의 영향
김관태;이해기;박병옥;
Kim, Gwan-Tae;Lee, Hae-Ki;Park, Byung-Ok;
경북대학교 신소재공학부 전자재료공학과;
School of Materials Science and Engineering, Dept. of Electronic Materials Science and Engineering, Kyungpook National University;
DOI : 10.5695/JKISE.2013.46.3.105
ZnS thin films were prepared on glass substrate by using chemical bath deposition method. The influence of ammonia ($NH_4OH$) and $Na_2EDTA$ ($Na_2C_{10}H_{16}N_2O_8$) as complexing agents on structural and optical properties of ZnS thin films were investigated. Zinc acetate dihydrate ($Zn(CH_3COO)_2{cdot}2H_2O$) and thiourea ($H_2NCSNH_2$) 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 (${alpha}$-ZnS) and had a preferred <101> orientation. ZnS thin films, with 4 M ammonia and with 4 M ammonia and 0.1 M $Na_2EDTA$, 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.