title: Improvement of optical transmittance and electrical properties for the Si quantum dot-embedded ZnO thin film.
abstract: A Si quantum dot (QD)-embedded ZnO thin film is successfully fabricated on a p-type Si substrate using a ZnO/Si multilayer structure. Its optical transmittance is largely improved when increasing the annealing temperature, owing to the phase transformation from amorphous to nanocrystalline Si QDs embedded in the ZnO matrix. The sample annealed at 700°C exhibits not only high optical transmittance in the long-wavelength range but also better electrical properties including low resistivity, small turn-on voltage, and high rectification ratio. By using ZnO as the QDs' matrix, the carrier transport is dominated by the multistep tunneling mechanism, the same as in a n-ZnO/p-Si heterojunction diode, which clearly differs from that using the traditional matrix materials. Hence, the carriers transport mainly in the ZnO matrix, not through the Si QDs. The unusual transport mechanism using ZnO as matrix promises the great potential for optoelectronic devices integrating Si QDs.
authors.forename: Kuang-Yang
authors.initials: KY
authors.lastname: Kuo
authors.forename: Chuan-Cheng
authors.initials: CC
authors.lastname: Liu
authors.forename: Pin-Ruei
authors.initials: PR
authors.lastname: Huang
authors.forename: Shu-Wei
authors.initials: SW
authors.lastname: Hsu
authors.forename: Wen-Ling
authors.initials: WL
authors.lastname: Chuang
authors.forename: You-Jheng
authors.initials: YJ
authors.lastname: Chen
authors.affiliation: Department of Photonics and Institute of Electro-Optical Engineering, National Chiao Tung University, 1001 Ta-Hsueh Road, Hsinchu 30010, Taiwan. potsung@mail.NCTU.edu.tw.
authors.forename: Po-Tsung
authors.initials: PT
authors.lastname: Lee