Wang Xiaolei, Sun Xupeng, Cui Shuainan, Yang Qianqian, Zhai Tianrui, Zhao Jinliang, Deng Jinxiang, Ruotolo Antonio
College of Physics and Optoelectronics, Faculty of Science, Beijing University of Technology, Beijing 100124, China.
Department of Natural Sciences, Florida Polytechnic University, 4700 Research Way, Lakeland, FL 33805, USA.
Sensors (Basel). 2021 Apr 25;21(9):3009. doi: 10.3390/s21093009.
Hall-effect in semiconductors has wide applications for magnetic field sensing. Yet, a standard Hall sensor retains two problems: its linearity is affected by the non-uniformity of the current distribution; the sensitivity is bias-dependent, with linearity decreasing with increasing bias current. In order to improve the performance, we here propose a novel structure which realizes bias-free, photo-induced Hall sensors. The system consists of a semi-transparent metal Pt and a semiconductor Si or GaAs to form a Schottky contact. We systematically compared the photo-induced Schottky behaviors and Hall effects without net current flowing, depending on various magnetic fields, light intensities and wavelengths of Pt/GaAs and Pt/Si junctions. The electrical characteristics of the Schottky photo-diodes were fitted to obtain the barrier height as a function of light intensity. We show that the open-circuit Hall voltage of Pt/GaAs junction is orders of magnitude lower than that of Pt/Si, and the barrier height of GaAs is smaller. It should be attributed to the surface states in GaAs which block the carrier drifting. This work not only realizes the physical investigations of photo-induced Hall effects in Pt/GaAs and Pt/Si Schottky junctions, but also opens a new pathway for bias-free magnetic sensing with high linearity and sensitivity comparing to commercial Hall-sensors.
半导体中的霍尔效应在磁场传感方面有广泛应用。然而，标准霍尔传感器存在两个问题：其线性度受电流分布不均匀性的影响；灵敏度与偏置有关，线性度随偏置电流的增加而降低。为了提高性能，我们在此提出一种新颖的结构，该结构可实现无偏置的光致霍尔传感器。该系统由半透明金属铂和半导体硅或砷化镓组成，形成肖特基接触。我们系统地比较了在无净电流流动情况下，取决于各种磁场、光强以及铂/砷化镓和铂/硅结的波长的光致肖特基行为和霍尔效应。对肖特基光电二极管的电学特性进行拟合，以获得势垒高度作为光强的函数。我们表明，铂/砷化镓结的开路霍尔电压比铂/硅结的低几个数量级，且砷化镓的势垒高度较小。这应归因于砷化镓中的表面态阻碍了载流子漂移。这项工作不仅实现了对铂/砷化镓和铂/硅肖特基结中光致霍尔效应的物理研究，而且与商用霍尔传感器相比，为具有高线性度和灵敏度的无偏置磁传感开辟了一条新途径。
