RETRACTED: Engineering the optical and electronic properties of Janus monolayer Ga2SSe by biaxial strain. (June 2019) - Jappor, Hamad Rahman; Obeid, Mohammed M.; Vu, Tuan V.; Hoat, D.M.; Bui, Hoi D.; Hieu, Nguyen N.; Edrees, Shaker J.; Mogulkoc, Yeşim; Khenata, Rabah