Room-temperature Domain-epitaxy of Copper Iodide Thin Films for Transparent CuI/ZnO Heterojunctions with High Rectification Ratios Larger than 10(9).
Room-temperature Domain-epitaxy of Copper Iodide Thin Films for Transparent CuI/ZnO Heterojunctions with High Rectification Ratios Larger than 10(9).
复制标题
DOI：
10.1038/srep21937
复制
发表时间：
2016-02-26
影响因子：
4.6
通讯作者：
Grundmann M
中科院分区：
文献类型：
--
作者：
Yang C;Kneiß M;Schein FL;Lorenz M;Grundmann M
CuI是一种p型透明导电半导体，具有独特的光电特性，包括宽带隙（3.1eV）、高空穴迁移率（块体>40cm2V−1s−1）和大的室温激子结合能（62meV）。 CuI外延的困难是其在先进固态电子器件中应用的主要障碍。在此，通过反应溅射技术实现了 CuI 在具有明确面内外延关系的各种衬底上的室温异质外延生长。在这种异质外延生长中，观察到旋转域的形成，并据此根据域外延的现有理论研究进行系统研究。 CuI 薄膜的可控外延允许 p 型 CuI 与合适的 n 型半导体组合，以制造外延薄膜异质结。这种异质结构比没有或有弱有序面内取向的结构具有更优异的性能。所获得的p-CuI(111)/n-ZnO(00.1)外延薄膜异质结表现出高达2 × 109 (±2 V)的高整流率，与具有无序界面的二极管相比提高了100倍。还形成低至5 × 10−9 Acm-2 的低饱和电流密度。这些结果证明了外延 CuI 作为一种有前景的 p 型光电材料的巨大潜力。
CuI is a p-type transparent conductive semiconductor with unique optoelectronic properties, including wide band gap (3.1 eV), high hole mobility (>40 cm2 V−1 s−1 in bulk), and large room-temperature exciton binding energy (62 meV). The difficulty in epitaxy of CuI is the main obstacle for its application in advanced solid-state electronic devices. Herein, room-temperature heteroepitaxial growth of CuI on various substrates with well-defined in-plane epitaxial relations is realized by reactive sputtering technique. In such heteroepitaxial growth the formation of rotation domains is observed and hereby systematically investigated in accordance with existing theoretical study of domain-epitaxy. The controllable epitaxy of CuI thin films allows for the combination of p-type CuI with suitable n-type semiconductors with the purpose to fabricate epitaxial thin film heterojunctions. Such heterostructures have superior properties to structures without or with weakly ordered in-plane orientation. The obtained epitaxial thin film heterojunction of p-CuI(111)/n-ZnO(00.1) exhibits a high rectification up to 2 × 109 (±2 V), a 100-fold improvement compared to diodes with disordered interfaces. Also a low saturation current density down to 5 × 10−9 Acm−2 is formed. These results prove the great potential of epitaxial CuI as a promising p-type optoelectronic material.