In optoelectronic devices based on two-dimensional (2D) semiconductor heterojunctions, the efficient charge transport of photogenerated carriers across the interface is a critical factor to determine the device performances. Here, we report an unexplored approach to boost the optoelectronic device performances of the WSe₂–MoS₂p–n heterojunctions via the monolithic-oxidation-induced doping and resultant modulation of the interface band alignment. In the proposed device, the atomically thin WO_x layer, which is directly formed by layer-by-layer oxidation of WSe₂, is used as a charge transport layer for promoting hole extraction. The use of the ultrathin oxide layer significantly enhanced the photoresponsivity of the WSe₂–MoS₂p–n junction devices, and the power conversion efficiency increased from 0.7 to 5.0%, maintaining the response time. The enhanced characteristics can be understood by the formation of the low Schottky barrier and favorable interface band alignment, as confirmed by band alignment analyses and first-principle calculations. Our work suggests a new route to achieve interface contact engineering in the heterostructures toward realizing high-performance 2D optoelectronics.

中文翻译：

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单片接口接触工程可提高2D半导体光伏异质结的光电性能

在基于二维（2D）半导体异质结的光电设备中，光生载流子在界面上的有效电荷传输是确定设备性能的关键因素。在这里，我们报告了一种未经探索的方法，可通过单片氧化诱导的掺杂和由此产生的对界面带取向的调制来提高WSe ₂ -MoS ₂ p - n异质结的光电器件性能。在提出的装置中，原子薄的WO _x层是通过WSe ₂的逐层氧化直接形成的用作促进空穴提取的电荷传输层。使用超薄氧化层的显著增强WSE的光响应_2个-MoS _2个p - Ñ结器件，并且功率转换效率从0.7增加至5.0％，保持响应时间。可以通过形成低肖特基势垒和良好的界面能带对准来理解增强的特性，这已经通过能带对准分析和第一性原理计算得到了证实。我们的工作提出了一条在异质结构中实现接口接触工程的新途径，以实现高性能2D光电。