Polycrystalline thin films of II-VI semiconductors on foreign polycrystalline (or amorphous) substrates have many applications in optoelectronic devices. In contrast to the extensive studies of the heteroepitaxial growth of compound semiconductors on single-crystal substrates, the nucleation and growth of thin films of II-VI compounds on foreign substrates have received little attention, and the properties of these films are often controlled empirically to optimize device performance. A better understanding of the nucleation, growth, and microstructure will facilitate a better control of the structural and electrical properties of polycrystalline semiconductor films, thereby improving the device characteristics. Cadmium telluride (CdTe) has long been recognized as a promising thin-film photovoltaic material. Under NREL's sponsorship, the University of South Florida has recently developed a record high efficiency (14.6% under global AM1.5 conditions) thin-film CdS/CdTe heterojunction solar cell for potential low-cost photovoltaic applications. The solar cell has the structure:glass (substrate)/SnO2:F/CdS/CdTe/HgTe (contact)The CdS films were grown from an aqueous solution, while the CdTe films were deposited by the closespaced sublimation method.
25.1% High‐Efficiency Monolithic Perovskite Silicon Tandem Solar Cell with a High Bandgap Perovskite Absorber