Faculty Sponsor(s)
Jennifer Heath
Location
Jereld R. Nicholson Library: Grand Avenue
Subject Area
Physics/Applied Physics
Description
While admittance measurements of solar cells are typically conducted in reverse or at zero bias, and analyzed using the depletion approximation, the operating point of the solar cell is in forward bias, and the series resistance is often estimated using IV curves with a high forward current. In this mode, the device is no longer in the depletion regime, and the large number of injected minority carriers alters the transport properties significantly. In our Cu(In,Ga)Se2 devices, we measure negative values of capacitance at high forward bias, which may be linked to injected minority carriers and carrier transport limitations, although our calculations of capacitance may also be influenced by series resistance. In this study, we compare AC and DC measurements of voltage dependent series resistance to try to better understand the negative capacitance signal.
Recommended Citation
Ogle, Alexander J.; Cox, Thaddeus J.; and Heath, Jennifer, "Frequency and Voltage Dependence of Series Resistance in a Solar Cell" (2016). Linfield University Student Symposium: A Celebration of Scholarship and Creative Achievement. Event. Submission 73.
https://digitalcommons.linfield.edu/symposium/2016/all/73
Frequency and Voltage Dependence of Series Resistance in a Solar Cell
Jereld R. Nicholson Library: Grand Avenue
While admittance measurements of solar cells are typically conducted in reverse or at zero bias, and analyzed using the depletion approximation, the operating point of the solar cell is in forward bias, and the series resistance is often estimated using IV curves with a high forward current. In this mode, the device is no longer in the depletion regime, and the large number of injected minority carriers alters the transport properties significantly. In our Cu(In,Ga)Se2 devices, we measure negative values of capacitance at high forward bias, which may be linked to injected minority carriers and carrier transport limitations, although our calculations of capacitance may also be influenced by series resistance. In this study, we compare AC and DC measurements of voltage dependent series resistance to try to better understand the negative capacitance signal.
