Toyo Solar, a subsidiary of Vietnamese solar manufacturer Vsun Solar completed the construction of a 4 GW TOPCon cell factory in the Hoà Phú Industrial Zone in the Bắc Giang province, in the northeast part of Vietnam.

The company said the facility represents the first phase of a project to build a cell factory with a total capacity of 8 GW. The $200 million facility is expected to reach completion in 2024.

Toyo Solar claims its TOPCon cells have a power conversion efficiency of 24.3% with a cell-to-module power retention ratio of over 99.8%.

Vsun is a unit of Japan-based electrical equipment company Fuji Solar Co Ltd and was founded in 2015. It currently also operates another cell and module factory in Vietnam's Bắc Giang province.