{"id":108450,"date":"2025-07-30T02:41:00","date_gmt":"2025-07-30T00:41:00","guid":{"rendered":"https:\/\/www.sonnenseite.com\/?p=108450"},"modified":"2025-07-30T09:34:44","modified_gmt":"2025-07-30T07:34:44","slug":"indoor-photovoltaics-with-over-40-percent-efficiency-developed","status":"publish","type":"post","link":"https:\/\/www.sonnenseite.com\/en\/science\/indoor-photovoltaics-with-over-40-percent-efficiency-developed\/","title":{"rendered":"Indoor photovoltaics with over 40 percent efficiency developed"},"content":{"rendered":"\n

Researchers at the Fraunhofer Institute for Solar Energy Systems ISE have succeeded in developing solar cells based on III-V semiconductors that can achieve an efficiency of over 40 percent indoors.

By the optimized design and improved quality of the solar cell absorber material , the research team achieved remarkably high efficiencies even under very low light conditions of just 100 lux. This result makes this technology particularly attractive for autonomous Internet of Things (IoT) applications that operate indoors without an external wired power supply. The findings were published in the journal Applied Physics Letters.<\/p>\n\n\n\n

Indoor photovoltaics use the artificial light indoors to generate electricity. This technology is particularly useful for devices that cannot be constantly charged, such as many components in IoT systems. \u201cVarious photovoltaic technologies can be used for this purpose,\u201d explains Dr. Henning Helmers, Head of Department at Fraunhofer ISE. \u201cSolar cells based on III-V semiconductors reach the highest efficiencies, this especially applies to artificial (LED) light.\u201d<\/p>\n\n\n\n

In their study, the researchers optimized gallium indium phosphide (GaInP) solar cells, as their band gap is almost ideal for converting visible light into electricity. “We investigated how well the solar cells with different architectures work under low light conditions”, summarizes Malte Klitzke, lead author of the study and scientist at Fraunhofer ISE. “It was shown that the n-doped GaInP cell performs significantly better than the p-doped cell. Charge carriers in n-doped GaInP cells have a longer lifetime, and thus they can produce more electricity even under weak light. This enabled us to achieve very high efficiencies with them in our experiments when converting weak indoor light into usable power.”<\/p>\n\n\n\n

The research result combines findings from several research projects: \u201c50Percent<\/a>\u201d, funded by the Federal Ministry of Economics and Climate Protection (BMWK), “H2Demo<\/a>“, funded by the Federal Ministry of Education and Research (BMBF) and \u201cSMART\u201d, supported by AZUR SPACE Solar Power and the German Space Agency (DLR).<\/p>\n\n\n\n