光栅局域调控二维光电探测器

近年来,二维材料独特的物理、化学和电子特性受到了越来越多的科研人员的关注.特别是石墨烯、黑磷和过渡金属硫化物等二维材料具有优良的光电性能和输运性质,使其在下一代光电子器件领域具有广阔的应用前景.本文将主要介绍二维材料在光电探测领域上的应用优势,概述光电探测器的基本原理和参数指标,重点探讨光栅效应与传统光电导效应的区别,以及提高光增益和光响应度的原因和特性,进而回顾光栅局域调控在光电探测器中的最新进展及应用,最后总结该类光电探测器面临的问题及对未来方向的展望.     

Negative photoconductivity in low-dimensional materials

In recent years,low-dimensional materials have received extensive attention in the field of electronics and optoelectronics.Among them,photoelectric devices based on photoconductive effect in low-dimensional materials have a broad development space.In contrast to positive photoconductivity,negative photoconductivity(NPC)refers to a phenomenon that the conductivity decreases under illumination.It has novel application prospects in the field of optoelectronics,memory,and gas detection,etc.In this paper,we review reports about the NPC effect in low-dimensional materials and systematically summarize the mechanisms to form the NPC effect in existing low-dimensional materials.     

带运输工具的网络流问题

考虑一个带运输工具的网络流问题。即由一个或者多个供应点向多个需求点通过桌种运输工具（比如货车、轮船等）供应货物的问题,目的是尽可能地降低供应成本．通过一个混和整数规划模型来描述这个问题．并利用拉格朗日松弛结合网络单纯形法得到原问题的一个下界．利用该下界结合试探法得到原问题的可行解．