MC-TPV355 Transient Surface Photovoltage Test System
Introduction: Solar photocatalysis generally uses semiconductor photocatalysts. The basic process of photocatalysis is generally divided into the following processes: electron hole generation, capture, recombination, migration and reaction. The kinetic process of photogenerated carriers in the photocatalyst is often carried out very fast, and the steady-state test and the positive method are often difficult to meet the requirements of the experiment. For example, for TiO2 catalysts, the characteristic time scale of some kinetic processes of photo-generated carriers is on the order of ns and μs, and some ultra-fast kinetic processes are completed within the time scale of ps and fs. Therefore, it is often necessary to use fast or ultra-fast time-resolved analysis and testing techniques for the study of the dynamics of photogenerated carriers in semiconductor photocatalysts. Transient photovoltage technology can be used to study the dynamic information of photogenerated charge distribution, including the drift and diffusion process in the process of photogenerated charge distribution: the drift process generally refers to the rapid distribution process that occurs in the particle; and the main dispersion The process is generally a long-term charge transfer between particles in the range of 1 division. In addition, by analyzing the shape, time scale, symbol, and intensity of the transient photovoltage spectrum, a series of information such as the speed of photo-generated charge separation and recombination, separation direction, separation mode, and degree of separation can be obtained. Transient surface photovoltage technology is an effective method to study the behavior of photogenerated charges on the nanosecond time scale. It has the advantages of non-contact and non-destructive. It can directly reflect the high direction of photogenerated charges, high efficiency, charge life and other dynamics. information. For photocatalytic reactions, the surface photovoltaic method is used to analyze the separation and transport process of photogenerated electron-hole pairs, which can explore the mechanism of charge recombination and provide guidance for improving the high efficiency of charge distribution. Technical Parameters: Laser, original imported Nd:YAG laser, pulse 1064nm, 532nm, 355nm, equipped with Merrychange adapter device Spot size: 6~8mm Digital oscilloscope, bandwidth: 1GHz Rise time 0.2 ns; Channel: 4 Sampling speed: 5-10GS/s Merrychange transient photovoltaic detection cell, which can analyze the sample as a catalyst powder material The sample that can be analyzed is a photoelectric device, the TPV signal is analyzed in the solution state, and the surface photovoltage signal and the electron diffusion length of the sample are tested. Preamplifier, 2 channels, DC~350MHZ bandwidth, rise and fall time 1ns, noise 6.4nv/HZ Imported energy meter, dual probes, energy test range: 10 μJ- 10 J All light paths are placed in a closed dark box, no external light source affects the analysis and testing. The interior is equipped with guide rails, reflectors, and a precision lifting platform, which can realize horizontal light paths or vertical light paths. Ferromagnetic stainless steel breadboard (900x1500x50mm), dark box, brand computer, control and data acquisition software Merrychange transient surface photovoltage testing software, dedicated hardware and software noise reduction algorithm, real-time collection and analysis of data to produce spectra, respectively, complete the analysis of powder samples and solution samples
Introduction: Solar photocatalysis generally uses semiconductor photocatalysts. The basic process of photocatalysis is generally divided into the following processes: electron hole generation, capture, recombination, migration and reaction. The kinetic process of photogenerated carriers in the photocatalyst is often carried out very fast, and the steady-state test and the positive method are often difficult to meet the requirements of the experiment. For example, for TiO2 catalysts, the characteristic time scale of some kinetic processes of photo-generated carriers is on the order of ns and μs, and some ultra-fast kinetic processes are completed within the time scale of ps and fs. Therefore, it is often necessary to use fast or ultra-fast time-resolved analysis and testing techniques for the study of the dynamics of photogenerated carriers in semiconductor photocatalysts. Transient photovoltage technology can be used to study the dynamic information of photogenerated charge distribution, including the drift and diffusion process in the process of photogenerated charge distribution: the drift process generally refers to the rapid distribution process that occurs in the particle; and the main dispersion The process is generally a long-term charge transfer between particles in the range of 1 division. In addition, by analyzing the shape, time scale, symbol, and intensity of the transient photovoltage spectrum, a series of information such as the speed of photo-generated charge separation and recombination, separation direction, separation mode, and degree of separation can be obtained. Transient surface photovoltage technology is an effective method to study the behavior of photogenerated charges on the nanosecond time scale. It has the advantages of non-contact and non-destructive. It can directly reflect the high direction of photogenerated charges, high efficiency, charge life and other dynamics. information. For photocatalytic reactions, the surface photovoltaic method is used to analyze the separation and transport process of photogenerated electron-hole pairs, which can explore the mechanism of charge recombination and provide guidance for improving the high efficiency of charge distribution.
