Fig. 1. (a) The equipment obtains energy through IPVs power generation under indoor lighting conditions. Reproduced from ref. 39 with permission from the [Wiley-VCH], copyright [2018]. (b) Emission spectra of different light sources. Reproduced from ref. 45 with permission from the [Elsevier], copyright [2019]. (c) Powered by IPVs of 1 square centimeter under indoor lighting and the corresponding drivable electronic equipment. Reproduced from ref. 39 with permission from the [Wiley-VCH], copyright [2018]. (d) The cost and market size of IPVs as a function of time (years). (e) Expected market size of different photovoltaic applications (2018–2027). (f) Manufacturing cost and annual production scale and indoor usage of different types of IPVs, (g) forecast of IPVs and WS market size, and (h) market demand for photovoltaic cells/modules in different energy demand fields (2016–2023). Reproduced from ref. 45 with permission from the [Elsevier], copyright [2019].