光电探测器响应时间实验研究-毕业设计论文

光电探测器响应时间实验研究

摘要

近几十年来，光电探测器在光通信、国防探测、信号处理、传感系统和测量系统等高精尖科技领域得到广泛的应用，在信息为导向的时代，时间就是生命，提高速度的需求日益紧迫，提高光电探测器响应速度的努力几乎从诞生它的一刻起就没停止过。本实验主要研究光敏电阻和光电二极管的响应时间。理论分析先从光敏电阻的光谱响应特性、照度伏安特性、频率响应、温度特性和前历效应来考察它的工作影响因素，确定光敏电阻响应时间与其入射光的照度、所加电压、负载电阻及照度变化前电阻所经历的时间的关系。从光电二极管的模型分析，我们知道光电二极管的响应时间有三个方面决定：①光生载流子在耗尽层附近的扩散时间；②光生载流子在耗尽层内的漂移时间；③与负载电阻并联的结电容所决定的电路时间常数。文中将详细分析计算对比三个时间的数量级，以确定提高响应速度的最有效途径，并提出改善光电二极管的有效方法和PIN 模型。实验研究时，采用近似脉冲的光源，经探测器的输出信号输入快速响应的CS-1022型示波器，在示波器上直接读出响应时间，分析实验结果，得出影响探测器响应时间的因素。

关键词：光电探测器，响应时间，半导体，影响因素

Abstract

In recent decades, photoelectric detectors have been widely used in high-tech areas such as optical communications, national defense detection and signal processing, sensing system and measurementsystem .in the era which leaded by information, time is life. Improving speed increasingly is urgent needs of photoelectric detector. To improve the response speed, effort haven't been stopped from birth to its moment. This experiment mainly researchs photoconductive resistance and photoelectric diode responsetime. The theoretical analysis studys photoconductive resistance properties, intensity of illumination volt-ampere characteristics, frequency response and temperature characteristic and former calendar effect to examine its working influence factors, and find out the influencing factors between photoconductive resistance response time and incident light intensity of illumination, voltage, load resistanceand the time experienced before intensity of illumination change. From the model analysis of the photoelectric diode, we know that the response time of the photoelectric diode has three aspects: (1) The diffusion time of photon-generated carrier near depletion layer.(2) The drift time of photon-generated carrier in depletion layer .(3) The constant of the circuit decided by junction capacitor which parallel with the load resistance . The detailed analysis and calculation of the order of magnitude of three time will be contrasted to determine the effective ways to improve photoelectric diode s' reaction speed,and the effective PIN model.In the experimental study, we use a pulse generator as light source, and the detector pulse output signal input quick response CS - 1022 type scillograph. So we can read direct response time in oscilloscope directly, then analyze the results, find out the factors which affect the probe response time.

Key word: Photoelectric detector, response time, semiconductor, influencing factors

1 绪论 (1)

1.1 光电探测器发展历程 (1)

1.2 近年高速探测器的发展成果 (2)

1.3 光电探测器的分类 (4)

1.4 光电探测器的物理基础 (6)

2 典型光电探测器响应时间的研究 (10)

2.1 光电导探测器. (10)

2.1.1 光电转换原理 (10)

2.1.2 工作特性分析 (12)

2.1.3 时间响应特性及改善 (17)

2.2 PN结光伏探测器 (17)

2.2.1 光电转换原理 (18)

2.2.2 光伏探测器的工作模式 (19)

2.2.3 Si 光电二极管的构造与特性分析 (21)

2.2.4 频率响应特性及改善探讨 (24)

3 光电探测器响应时间实验研究 (32)

3.1 实验原理 (32)

3.1.1 脉冲响应 (32)

3. 1 .2幅频特性 (33)

3.2实验仪器 (34)

3.3 实验步骤 (35)

3.4 实验结果与分析 (37)

结论 (39)

参考文献 (40)

致谢 (41)