强度调制的光电化学扫描频谱仪的研究

发布时间：2018-07-13 21:25

【摘要】：近年来，太阳能作为一种可替代的清洁能源日益受到社会的广泛关注，随之而来的是光伏发电、太阳能电池的研究热潮。目前发展最快的是动态光谱调制阻抗谱扫描测试方法IMPS(Intensity Modulated Photocurrent)/IMVS (Photovoltage Spectroscopy)，它实现了动态调制光谱强度的同时完成阻抗测量及阻抗谱的绘制。在电化学应用领域，传统的频谱扫描是由电化学工作站完成，由于电化学工作站针对常规电化学实验方法设计，无法实现动态调制光电光谱的功能，亦无法实现两者精准的同步控制。在硬件设计方面，，传统电化学工作站基于单片机设计，使用逻辑器件来实现其功能扩展，进而实现DDS输出及信号采集、存储控制等功能。但随着电化学研究的不断深入，对实验设备的响应速度、测量精度提出越来越高的要求，硬件结构及软件设计也越来越复杂，传统设计方案已经无法满足不断更新的实验要求。该论文以光谱电化学测量为基础，基于ARM平台及高速高精度模数混合电路提出了一套强度调制的光电化学扫描频谱仪的设计方案，并完成了设计方案的硬件设计及测试工作。该设计方案包括以下内容：基于AD7671的双通道数据采集器、基于FPGA设计的任意信号发生器（DDS）、高精度恒电位仪、高精度恒电流仪、频率响应分析仪（FRA）、iR降补偿电路、多级信号放大、多段可选巴特沃斯低通滤波器以及USB、TCP/IP隔离通信。最后，配合光强调制设备完成了标准体系的阻抗谱扫描测试，测试结果：DDS正弦输出频率范围10uHz-1MHz，频率控制精度0.01%以内；阻抗测试范围在10-3-1011，技术指标达到设计要求。
[Abstract]:In recent years, solar energy as a kind of alternative clean energy has been paid more and more attention by the society, followed by the research boom of photovoltaic power generation and solar cells. At present, the fastest development is IMPS (intensity modulated current) / IMVS (Photovoltaic Spectroscopy), which realizes the measurement of impedance and the rendering of impedance spectrum simultaneously. In the field of electrochemical application, the traditional spectrum scanning is accomplished by the electrochemical workstation. Because the electrochemical workstation is designed for the conventional electrochemical experimental method, it can not realize the function of dynamically modulating the photoelectric spectrum. They can not achieve accurate synchronization control. In the aspect of hardware design, the traditional electrochemical workstation is designed on the basis of single chip microcomputer. The logic device is used to realize the function expansion, and then the functions of DDS output, signal acquisition, storage and control are realized. However, with the deepening of electrochemical research, the response speed and measurement accuracy of the experimental equipment are required more and more, and the hardware structure and software design are becoming more and more complex. The traditional design scheme can not meet the requirements of the constantly updated experiment. Based on the spectroelectrochemical measurement, this paper presents a design scheme of the intensity modulated photoelectrochemical scanning spectrometer based on arm platform and high speed and high precision analog / digital hybrid circuit. The hardware design and testing work of the design scheme are also completed. The design includes the following contents: a dual-channel data acquisition device based on AD7671, an arbitrary signal generator (DDS) based on FPGA, a high-precision potentiostat, a high-precision constant current meter, a frequency response analyzer (FRA) / iR compensation circuit, and multistage signal amplification. Multistage optional Butterworth lowpass filter and USB TCP / IP isolated communication. Finally, the impedance spectrum scanning test of the standard system is completed with the light intensity modulation equipment. The test results show that the frequency range of sinusoidal output is 10uHz-1MHz, and the precision of frequency control is less than 0.01%, and the impedance measurement range is 10-3-1011.The technical specifications meet the design requirements.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM935.21

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