Temperature changes of I-V characteristics of photovoltaic cells as a consequence of the Fermi energy level shift

Abstract

Photovoltaic (PV) energy conversion has grown in importance in the past decade. Number of large PV power plants with nominal power of the order of tens of MW p and a number of smaller PV systems on the roofs were installed (Poulek, Libra 2010). Most of them were installed in Europe, mainly in connection with the subsidy policies of some countries.It is known that changes in operation temperature cause changes of current and voltage of PV cells and PV modules (i.e. I-V characteristic). Increasing temperature decreases the open-circuit voltage. This effect simultaneously increases the short-circuit current (Orioli, Di Gangi 2013; Barukcic et al. 2014; Baig et al. 2015). The efficiency of the photovoltaic energy conversion thus decreases with the increasing temperature (Karatepe et al. 2007). In this paper, this phenomenon is theoretically explained by the theory of solid state physics (Pikus 1965;Snejdar, Frank 1976;Kittel 2005). Similar problems were discussed previously (Carrero et al. 2011;Liu et al. 2011;Ding et al. 2014) in case of common solar cells or by (Strebkov 2010) in case of matrix solar cells. The I-V and P-V characteristics of partially shaded PV system were also discussed (Kofinas et al. 2015). The increasing temperature causes a narrowing of the forbidden gap and a shift of the Fermi energy level toward the centre of the forbidden gap. Both these effects lead to a reduction of the potential barrier in the band diagram of the illuminated PN junction, and thus to a decrease of the photovoltaic voltage. In addition, narrowing of the forbidden gap causes higher generation of electron-hole pairs in the illuminated PN junction and short-circuit current increases.

Changes in the Efficiency of Photovoltaic Energy Conversion in Temperature Range With Extreme Limits

“…For example, in the work [29], similar dependences were measured in the temperature range +25°C to +80°C. We measured similar dependences in the temperature range −15°C to +35°C [27]. Even in other works, we did not find a measurement in the temperature interval below −15°C.…”

Modelado matemático de un colector solar fotovoltaico-térmico híbrido para evaluación del desempeño térmico en Cd. Juárez Chihuahua

“…Another important parameter in the study of photovoltaic modules is the temperature response with respect to the change in incident radiation, which is considered dynamic and cannot be analyzed in detail in a stationary model. For this reason, various stationary and dynamic models have been studied to determine said time constant, in addition to the effects that cell temperature causes on energy conversion, as well as the non-linearities of the system, as is showed in (Armstrong, S., & Hurley, W. G., 2010), (Sadeghzadeh, M., Ahmadi, M. H., Kahani, M., Sakhaeinia, H., Chaji, H., & Chen, L., 2019), (Patel G. A., 2016), (Manjunath, M. S., Karanth, K. V., & Sharma, N. Y., 2018), (Libra M., Poulek V., Kouřím P., 2017), (Yeshalem M. T. and Khan B., 2017), (Singh, A. P., & Singh, O. P., 2018).…”

Modelling and simulation of photovoltaic cell in MATLAB

“…Solar Photovoltaic (SPV) modules or panels are prepared from semiconductors usually of extrinsic silicon (Si) termed as photovoltaic cell which receive solar radiation as input energy and convert it into electricity directly. Photovoltaic (PV) cells, facilitate the conversion of solar energy directly into electric (DC) power by the photoelectric principle (Martin et al, 2017), which can be used to drive electrical loads and can be stored in batteries or fed directly into a power grid. PV systems are gaining popularity because of government initiatives in gradual cost reduction, non-incurrence of any maintenance and running cost technologically and no pollution generation.…”