A Bangladeshi-Japanese research team has built a copper silver bismuth iodide (CABI) photovoltaic device using the unexplored CABI compound. The researchers used a mixed solvent-based hot casting technique to improve the surface morphology of the CABI membrane and increase cell efficiency.
“The construction of CABI-based solar cells is not new,” said Arif Ul Islam, lead author of the study. pv magazinenotes that two previous attempts to build this cell technology were based on CABI materials known as CuAgBiI5 and Cu2AgBiI6, resulting in an efficiency of 1.01% and 2.39%. “However, our work is the first attempt to build a solar cell based on it Cu6AgBiI10which is a special CABI material.”
The researchers used a mixed solvent-based hot casting technique to improve the surface morphology Cu6AgBiI10 a film they said was intended to achieve the highest possible solar power output. They used a one-step spin-coating technique in which hot-cast droplets were cast onto preheated substrates.
“The solution was spin-coated at 3000 rpm for 30 seconds,” they explained, adding that the thickness of the CABI films ranged from 1183 to 1506 nm. “The films were then annealed in the glove box at 75°C for 3 minutes and then heated at different temperatures (130-170°C) for six minutes on a hot plate. The films were then allowed to cool naturally to ambient temperature.
The film was used as an absorber in a PV device made of a substrate of indium tin oxide (ITO) and glass, an electron transport layer (ETL) based on tin(IV) oxide (SnO)2), the absorber itself, the hole transport layer (HTL). polymer Regioregular poly(3-hexylthiophene) (P3HT) and silver (Ag) metal contact.
The research team analyzed the optical properties of the cell and found that it could achieve a power conversion efficiency of 0.041% and a maximum current density of 0.45 mA/cm.2, under ambient conditions. “Our optical study revealed high absorbance and low reflectance of the CABI film at 150 C,” it also stated.
“Bismuth is abundant in the earth’s crust, which makes it cost-effective,” stressed Islam. “Our results should be useful for the development of environmentally friendly Cu-Ag-Bi-I based solar cells as well as many other devices such as photodetectors or LEDs.”
The solar cell architecture is presented in the article “Improved surface morphology and photovoltaic properties for a new material class copper-silver-bismuth iodide solar cell”, published Journal of Materials Research and Technology. The research team consists of researchers from Bangladesh’s Barishal University and Japan’s Nagoya Institute of Technology.