The Development of the I-V Measurement by Pulsed Multi-Flash, and the Effectiveness
In order for the device to measure the I-V characteristics of the photovoltaic (PV) module to be used in the PV module assembly line, easy handling of the module, improvement of measurement accuracy, and reduction of the measuring time are strongly requested. We developed the solar simulator with several milliseconds flat pulsed light of multi flashes and accomplished the improvement of measurement accuracy, and the reduction of the measuring time. Both I-V measuring device and measuring method we developed are also effective in estimating the characteristics of response, light induced change, and being newly developed PV modules
Sunlight based I-V characterization of solar PV cells
A family of current as a function of voltage (I-V) curves under different illumination conditions as specified in standards are needed to characterize a photovoltaic (PV) cell. Instead of using an artificial light as the source, a method of using sun light through fiber optic cables is described to obtain the I-V characteristics of a PV cell. Moreover, an electronic load realized with a MOSFET as a variable resistor, in conjunction with microcontroller based instrumentation automates the testing process. A prototype I-V curve tracer, developed and tested, establish the efficacy of the proposed method.
The superlinearity of the short-circuit current of low-resistivity-concentration solar cells
It has been observed that Si solar cells respond superlinearly to irradiance while GaAs behaves linearly. Computer analysis of superlinear characteristics of short-circuit current with irradiances above 1 sun for low-resistivity Si concentrator cells has shown the importance of the base electric field in enhancing the collection efficiency of minority carriers generated in the base region. The effect of the base electric field can be incorporated into effective upstream and downstream diffusion lengths. The effective downstream diffusion length increases from 223 mu m at one sun to near 1000 mu m at 1000 suns in one case. Collection of minority carriers in the base alone due to the enhanced diffusion lengths is sufficient to explain the observed superlinearity. >