Solar-Tectic LLC of Briarcliff Manor, New York USA, reported that the U.S. Patent and Trademark Office has awarded the company two patents for perovskite thin film solar cells. One patent covers all types of perovskites. The inventors are Ashok Chaudhari, founding manager of Solar-Tectic, and the renowned materials physicist, the late Dr. Praveen Chaudhari.
The breakthrough patents (U.S. 9,722,130 and 9,978,532) correspond to a “Tandem Series” of solar cell technologies which ST has launched including a variety of proven semiconductor photovoltaic materials (such as III-V, CZTS, a-Si, and others) for the top layer on a silicon (or germanium) bottom layer, on various substrates such as cheap soda-lime glass.
Also, the USPTO granted ST a U.S. patent (9,997,661) for a copper oxide thin-film tandem solar cell this month, expanding the company’s IP portfolio of the tandem series.
Solar-Tectic boasts that its thin-film crystalline inorganic bottom layers can be as thin as 20-30 microns compared to the 200-280 microns thick for silicon layers in PERC, PERL, HIT, HJ, or perovskite/silicon tandem cells. At the same time the company says that the its tandem cells achieve the same or similar efficiency and its bottom silicon layers can be processed at much lower temperatures.
The top perovskite layer has a thickness of only 1 micron. Also, a thin film crystalline silicon (CSiTF) bottom layer decouples the need for a silicon wafer. Solar-Tectic has set a realistic 30% efficiency goal. This efficiency would be higher than the best silicon wafer technologies such as PERC, PERL, HIT, HJ cells with 25-26.6% efficiencies.
ST boasts that the entire ST process is environmentally friendly because of its use of non-toxic Sn (tin) or Au (gold) to deposit the crystalline silicon thin-film material for the bottom layer in the tandem/heterojunction configuration, and in the top, perovskite, layer. Toxic lead Pb is not used, according to ST.