The rapid development of the Internet of Things (IoTs) demands self-powered indoor devices to supply continuous power. Thus, developing an efficient photo-storage device that is capable of harvesting and storing indoor light energy requires detailed performance analysis of suitable solar cells. Herein, a comparative study of the performance of photo-storage systems based on three different solar cell technologies in combination with symmetric non-volatile supercapacitors was performed. Considering the advantages of hybrid solar cells such as low-cost fabrication and high photovoltaic response under diffused light, perovskite solar cells (PSCs) and dye-sensitized solar cells (DSCs) were selected, and the photo-storage efficiencies were compared with crystalline silicon solar cells (crystalline Si–SCs) under outdoor (Xe light irradiation: 1–100 mW cm−2) and indoor white Light Emitting Diode (LED) (1–20 mW cm−2) illumination. Photovoltaic performance was compared using current-voltage (IV), maximum power point tracking (MPPT), and charging of supercapacitor, either directly or through a DC-DC converter. The highest efficiencies were observed with PSCs under low light intensity, using Xe light and white LED light conditions. Despite the anomalous hysteresis behavior, IV analysis of the PSCs showed efficiency above 12% under Xe light irradiation and above 20% using white LED lighting (extracted from the reverse scan and at light intensity intervals of 1–20 mW cm−2). The determination of real-time efficiencies at MPP for PSCs showed a temporary efficiency drop at each intensity under white LED light, which is more significant for longer illumination times. However, under low light-intensity, single PSCs showed only a slight average voltage drop of 800 to 700 mV in comparison with a considerable drop of 800 to 500 mV at MPP for two series-connected crystalline Si–SCs. In addition, single PSC was able to show better power delivery efficiencies (PDEs) and supply the required minimum operating voltage for the DC-DC boost converter at 1–20 mW cm−2 where two series solar cells are required for DSCs and crystalline Si–SCs. The overall efficiencies for the DC-DC boost converter charging dropped towards low intensities from 9 to 5% and 8.5 to 2.7% for PSCs and crystalline Si–SCs, respectively. This decrease was mainly due to the loss of converter efficiency at low input powers which could be negligible on large-scale solar cells. Furthermore, in direct charging, PSC provided over 8.5% stable overall efficiencies with about 80% storage efficiency under white LED light intensities ranging from 1 to 20 mW cm−2 at the areal discharge, and were able to maintain high overall peak efficiencies of 5.6 and 4.1% at high areal discharging currents of 18 and 30 mA cm−2, respectively. This study demonstrates the suitability of photo-supercapacitor systems combining PSCs and carbon-based supercapacitors for continuous power-up of indoor high-current-requirement IoT devices.
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