Are ordinary panels a thing of the past? The Chinese have something better
Scientists from China prove that standard photovoltaic panels could face competition. They managed to develop a thin-film cell, whose efficiency is satisfactory, and which requires less silicon for its construction than standard cells.
7:59 AM EDT, October 8, 2023
Scientists from Hangzhou Dianzi University in China have produced a thin-film monocrystalline cell that may compete in efficiency with standard cells. As reported in PV magazine, the cell built in China has a thickness of 0.000787 inches, which is eight times less than the typical "thick" cell with a thickness of about 0.0063 inches.
For the production of the cell, scientists used layer transfer methods instead of cutting silicon ingots. Layer transfer is a technique that involves transferring a layer of semiconductor material, often the size of a single wafer, from the original substrate to the target location.
This method involves the use of hydrofluoric acid. First electrochemically, for etching pores in a thick silicon plate. This plate is used as a substrate for the epitaxial growth of a monocrystalline layer of silicon. Then, such a layer is peeled off from the porous silicon substrate.
This process allowed for the creation of a monocrystalline plate with a thickness of 0.000787 inches. Subsequently, the scientists deposited many passivation layers on it using Plasma Enhanced Chemical Vapor Deposition (PECVD), which were made of aluminum oxide, silicon nitride, and silicon oxide.
"Compared to the standard solar cell used as a reference point, the current density increased from 220.7 mA/in2 to 246.2 mA/in2," we read in the scientists' publication. The open circuit voltage of the cell also increased from 0.632V to 0.684V.
As a result of the scientists' work, the fill factor increased from 76.2% to 80.8%. In addition, the cell efficiency also clearly increased - from 16.5% to 21.1%.
