Design Of Intensity Modulated Photo Spectroscopy

In recent years, the solar power as an alternative clean energy is growinglywidespread concern in society，Followed by photovoltaic, solar cells research boom.Currently，the method widely used by the scientific field is static/dynamic test methods, andthe dynamic photo modulation spectroscopy IMPS/IMVS is so far the latest and most rapiddevelopment voltage/current testing technology. In the field of electrochemical energy-research, the traditional spectrum scanning is completed by electrochemical-workstation.Due to the electrochemical-workstation designed for conventional electrochemicalexperiment, it is unable to realize dynamic modulation function of photoelectric spectrum,and is unable to realize the accurate synchronization operation. The traditionalelectrochemical workstation is designed based on simple MCU controller；Logic devicesare used to achieve its extended function, and then realize the DDS output, data collectionand storage operation. Nevertheness, with the deepening of the electrochemical studies theresponse speed of testing equipment and the measurement precision made increasingdemands, and then the structure of the logic system is becoming more and morecomplicated, the traditional design scheme has been hard to meet the demand.In this paper, the spectral electrochemical measurement as a starting point, and a set ofintensity-modulated photoelectrochemical scanning spectrometer design based on ARMplatforms and high-speed high-precision analog-digital hybrid circuit design and carry outthe verification of the principle. Main program includes: Arbitrary Wave Generator (AWG)Based on ARM and FPGA platforms, dual-channel data acquisition based on the AD7671,high-precision potentiostat, high-precision galvanostat, FRA, iR drop compensationcircuit,multi-level amplification, multi-segment optional Butterworth LPF and isolatedUSB,TCP/IP communication module.Finally, complete the impedance spectrum scanning test by using the spectroscopyequipment with the photo intensity modulation, test results: the Sine frequency from DDSranged in the10uHz to1MHz,and frequency control precision is within0.01%; Impedancetest ranged in the10-3-1011.