High　hydrogen　content　(C-H)　intrinsic　amorphous　silicon　(a-Si:H)　buffer　layers　were　deposited　on　both　sides　of　crystalline　silicon　wafers　using　plasma-enhanced　chemical　vapor　deposition　technique,　which　significantly　improved　surface　passivation　as　well　as　conversion　efficiency　of　the　silicon　heterojunction　solar　cells.　Properties　of　the　buffer　layer　and　impact　on　the　device　performance　were　investigated.　High　resolution　transmission　electron　microscope　characterization　shows　that　no　obvious　epitaxial　growth　occurred　at　the　interface　as　long　as　a-Si:H　buffer　layer　was　introduced　between　c-Si　and　bulk　intrinsic　layer.　Further　study　indicates　that　minority　carrier　lifetime　of　the　device　is　related　to　hydrogen　content　of　the　buffer　layer,　reaching　highest　value　up　to　2050　ms　at　C-H　of　33%.　These　findings　evidently　confirmed　that　suppression　of　epitaxial　growth　and　thus　improved　passivation　were　realized　by　using　high-hydrogen-content　a-Si:H　buffer　layer,　based　on　which　a　high　efficiency　solar　cell　was　prepared　with　large　area.