PLD法生长n-Zn_(1-x)Co_xO/p-Si异质结的电学性能研究

Electrical Characteristic of n-Zn_(1-x)Co_xO/p-Si Films Grown by PLD

用高功率脉冲激光轰击Zn1-xCoxO,得到锌、钴和氧的原子、分子和团簇等混合体,并在p型单晶Si表面反应生成n型Zn1-xCoxO。X射线衍射(XRD)、原子力显微镜(AFM)研究表明,这层材料是结构致密均匀、呈c轴高度择优取向的薄膜,与p型Si材料形成n-Zn1-xCoxO/p-Si异质结。在Zn1-xCoxO中加入H,生成了Co—H—Co聚合体,异质结的势垒高度随着Co含量的增加而增加,同时深能级的Co—d轨道捕获作为浅施主的间隙H提供的电子,造成的体系n型半导体层的载流子浓度降低,电阻率提高,使得n-Zn1-xCoxO/p-Si异质结在6.5V时漏电流降致6×10-3mA,反向击穿电压超过20V,电学性能得到显著改进。

X-ray diffraction,atomic force microscopy,and I-V expcriments n-Zn1-xCoxO/p-Si films deposited on p-Si （100） substrates by pulsed laser deposition （PLD） under a low hydrogen pressure （9× 10^-5 torr） shows highly c-axis oriented and good electrical characteristics,which was characterized by. The barrier heights of the heterojunctions calculated increases from 0. 6 to 0. 7eV with the content of Co in the atmosphere of hydrogen. This result is attributed to Co-H-Co complexes forming and the deep Co-d level in a Co dimer capturing the shallow donor electron of anisolated interstitial H. The carries density of n-Zn1-xCoxO layer decreases and the resistance enhances,leading to good electrical characteristics that the leakage current was decreased to 6 × 10^- 3mA at 6.5V reverse bias and the breakdown voltage was over 20V.