近日，浙江大学的狄大卫&赵保丹及其研究团队取得一项新进展。经过不懈努力，他们对发射型钙钛矿半导体的可控p型和n型行为进行研究。相关研究成果已于2024年9月11日在国际权威学术期刊《自然》上发表。

本研究报道指出，通过在宽带隙钙钛矿半导体中掺入具有强吸电子能力的膦酸分子掺杂剂，可以调整其p型和n型特性。由此得到的p型和n型样品的载流子浓度均超过10¹³cm^-3，霍尔系数范围从0.5m³C^-1（n型）到0.6m³C^-1（p型）。观察到费米能级在带隙间的移动。

重要的是，在保持70–85%的高光致发光量子产率的同时，实现了从n型到p型电导率的转变。在发光钙钛矿半导体中实现的可控掺杂，使得具有简单结构的钙钛矿发光二极管展现出超高亮度（超过1.1×10⁶cdm^-2）和卓越的外部量子效率（28.4%）。

据悉，对半导体中电导率及其极性的可靠控制是现代电子技术的核心，并已催生出包括二极管、晶体管、太阳能电池、光探测器、发光二极管和半导体激光器等关键发明。对于典型的半导体，如硅（Si）和氮化镓（GaN），正（p）型和负（n）型电导率分别通过向晶体晶格中掺杂电子受体和电子给体元素来实现。然而，对于卤化物钙钛矿这一新兴半导体类别，尚未发现能在保持高光电性能的同时，可靠控制电荷传导行为的机制。

附：英文原文

Title: Controllable p- and n-type behaviours in emissive perovskite semiconductors

Author: Xiong, Wentao, Tang, Weidong, Zhang, Gan, Yang, Yichen, Fan, Yangning, Zhou, Ke, Zou, Chen, Zhao, Baodan, Di, Dawei

Issue&Volume: 2024-09-11

Abstract: Reliable control of the conductivity and its polarity in semiconductors is at the heart of modern electronics, and has led to key inventions including diodes, transistors, solar cells, photodetectors, light-emitting diodes and semiconductor lasers. For archetypal semiconductors such as Si and GaN, positive (p)- and negative (n)-type conductivities are achieved through the doping of electron-accepting and electron-donating elements into the crystal lattices, respectively. For halide perovskites, which are an emerging class of semiconductors, mechanisms for reliably controlling charge conduction behaviours while maintaining high optoelectronic qualities are yet to be discovered. Here we report that the p- and n-type characteristics in a wide-bandgap perovskite semiconductor can be adjusted by incorporating a phosphonic acid molecular dopant with strong electron-withdrawing abilities. The resultant carrier concentrations were more than 10¹³cm^-3 for the p- and n-type samples, with Hall coefficients ranging from 0.5m³C^-1 (n-type) to 0.6m³C^-1 (p-type). A shift of the Fermi level across the bandgap was observed. Importantly, the transition from n- to p-type conductivity was achieved while retaining high photoluminescence quantum yields of 70–85%. The controllable doping in the emissive perovskite semiconductor enabled the demonstration of ultrahigh brightness (more than 1.1×10⁶cdm^-2) and exceptional external quantum efficiency (28.4%) in perovskite light-emitting diodes with a simple architecture.

DOI: 10.1038/s41586-024-07792-4

Source: https://www.nature.com/articles/s41586-024-07792-4