An international research group led by Longi Central R&D Institute has published a paper describing Longi's heterojunction solar cell based on a full-size silicon wafer that made a sensation in November, as it beat the long-lasting efficiency record held by Japanese manufacturer Kaneka for years. The researchers attributed the cell efficiency improvement to the implementation of a p-type amorphous silicon hydrogenated layer together with a modified transparent conductive oxides contact, which they said greatly reduced the cell contact resistivity.