Analytical Modeling of the Dependence of the Open-Circuit Voltage With Temperature in CMOS Photodiodes

The open-circuit voltage is a key parameter determining the harvesting capabilities of diodes operating in photovoltaic regimes. It depends on illumination and temperature which may limit the diode operation in some scenarios. Its dependence on illumination has already been reported. However, the latter has not been studied for diodes integrated into standard IC fabrication technologies. The model was validated with TCAD simulations within a wide operation range. In addition, the model was validated with experimental results. Diodes operating in photovoltaic mode were implemented in two different 180-nm fabrication technologies and characterized. Comparative results show the model qualifies to study how temperature variations can impact the performance of solar cells.