(02 July - 30 July, 2009), School of Materials and Mineral Resources Engineering, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang, Malaysia.
(20 July - 13 August, 2010), Low Dimensional Materials Research Centre (LDMRC), Department of Physics, Faculty of Science, University of Malaya, 50603 Kuala Lumpur, Malaysia.
(08 June - 26 June, 2014), Department of Electrical Engineering, Center for Advanced Photovoltaics, South Dakota State University, Brookings, SD 57007, USA.
(01 November - 30 November 2017), Department of Electrical Engineering, Center for Advanced Photovoltaics, South Dakota State University, Brookings, SD 57007, USA.
(02 July - 16 July 2023), Institute of Functional Nano & Soft Materials (FUNSOM), Soochow University, Dushu Lake Campus, Suzhou Industrial Park Suzhou, Jiangsu, 215123, P.R. China.