Abstract:The photon absorption and response mechanism of photovoltaic semiconductor detectors has been a hot topic in the field of semiconductor photoelectric detection. In recent years, with the wide application of photovoltaic detectors in the field of Fourier transform infrared (FTIR) spectroscopy detection, the nonlinear response of photovoltaic devices has increasingly become a key issue affecting the accuracy of FTIR spectroscopy inversion. Therefore, the study of the response nonlinearity of photovoltaic detectors can not only reveal the response law of semiconductor devices to different flux radiation, but also has important application significance for improving the nonlinear problem of photovoltaic detectors and improving the detection accuracy of FTIR spectroscopy. Firstly, the general principle and equivalent circuit of the photovoltaic detector are summarized, and then the internal effects and external factors leading to the nonlinear response of the detector are analyzed. Finally, the correlation between the internal and external factors is summarized, and the working direction of nonlinear correction of the detector is given in the conclusion.