This article proposes a photovoltaic system of ultrathin silicon solar cell by using indoor lighting through enhanced shunt resistance, nanostructure of light-trapping, and tubular daylight system for powering the internet of things (IoT) devices. Simulation results show that, by increasing the shunt resistance from 100 Ω.cm2 to 104 Ω.cm2, the efficiency of indoor solar cell can be improved from less than 0.5% to be over 14%. Moreover, with the help of ultrathin wafer and nanostructure of light-trapping to improve the near-infrared light absorption and open circuit voltage, the efficiency of the indoor amorphous silicon (a-Si) heterojunction solar cell can be further improved to be 17.09%. The tubular daylight system is an excellent supplement to the light indoor intensity and thus can increase the power production.