中长波红外光电探测新模式的探索

中长波红外光电探测器在光电技术领域具有重要的应用，然而传统的半导体红外探测器因为复杂的原因始终受高暗电流困扰，从而使其性能下降，应用也受到严重限制。我们提出一种铁电/半导体隧道结用于对中长波红外辐射进行探测。在这种结构中，铁电隧道结的隧道效应与窄禁带半导体的光电效应进行结合，并利用铁电极化对半导体电子态进行调控，通过其耗尽态在光照下形成的光伏效应实现对中长波红外光子的有效感知。研究影响铁电/半导体隧道结光伏效应的各种因素，揭示铁电极化局域场作用光电响应机理。并分析光生载流子拆分、扩散等输运过程，揭示暗电流产生机理。设计、制备出高响应率的新型中长波红外光电探测原型器件，为发展实用型、高性能中长波红外光电探测器提供理论基础和科学依据。

Mid-/long-wavelength infrared photodetectors have important applications in the opoto-electronic technical fields. Suffered from high dark currents for multiple reasons, the performance of the traditional semiconductor infrared detectors is substantially degraded, and its applications are also severely limited. We propose a new structure based on ferroelectric/semiconductor tunnel junction to detect the mid-/long-wavelength infrared radiations. The tunneling effect of the ferroelectric tunnel junction couples with the optoelectronic effect of the narrow bandgap semiconductor in the structure under the infrared radiations. And the electronic states of the semiconductors can be modified by the direction of the ferroelectric polarization. In the case of depletion state, a photovoltaic effect happens under infrared radiations. Investigate the effects of the various factors on the photovoltaic effect, and reveal the mechanisms of the origin of the photovoltaic effect. Analyze the separation, diffusion, and transition of the photon-generated carriers, and reveal the mechanism of the dark current of the ferroelectric/semiconductor tunnel junctions. Design and prepare the new infrared photodetectors with high responsivity, and provide the theoretical knowledges and scientific evidences for the practical mid-/long-wavelength infrared photodetectors with high performance.