Al‐Doped Black Phosphorus p–n Homojunction Diode for High Performance Photovoltaic

• Published in: Advanced functional materials 2017-02, Vol.27 (7), p.np-n/a
• Main Authors: Liu, Yuanda, Cai, Yongqing, Zhang, Gang, Zhang, Yong‐Wei, Ang, Kah‐Wee
• Format: Article
• Language: English
• Subjects: Aluminum; Al‐doping; Bias; black phosphorus; Dark current; Decay; Diodes; Doping; Electric potential; Electrical junctions; Heterostructures; Homojunctions; Layered materials; Materials science; P-n junctions; Phosphorus; Photovoltaic cells; photovoltaics; Short circuits; Signal to noise ratio; Solar cells; Stability; Unity
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.201604638

2D layered materials based p–n junctions are fundamental building block for enabling new functional device applications with high efficiency. However, due to the lack of controllable doping technique, state‐of‐the‐art 2D p–n junctions are predominantly made of van der Waals heterostructures or electrostatic gated junctions. Here, the authors report the demonstration of a spatially controlled aluminum doping technique that enables a p–n homojunction diode to be realized within a single 2D black phosphorus nanosheet for high performance photovoltaic application. The diode achieves a near‐unity ideality factor of 1.001 along with an on/off ratio of ≈5.6 × 103 at a low bias of 2 V, allowing for low‐power dynamic current rectification without signal decay or overshoot. When operated under a photovoltaic regime, the diode's dark current can be significantly suppressed. The presence of a built‐in electric field additionally gives rise to temporal short‐circuit current and open‐circuit voltage under zero external bias, indicative of its enriched functionalities for self‐powered photovoltaic and high signal‐to‐noise photodetection applications. 2D p–n junction is a fundamental building block for nanoelectronics devices, which has been predominantly realized using van der Waals heterostructures or electrostatic‐gated junctions due to the lack of controllable doping techniques. Here, near‐ideal black phosphorus p–n homojunction diodes are achieved by novel and facile Al‐atom doping, paving the way toward high performance photovoltaic applications.