[20p-C101-1~17] 16.3 Bulk, thin-film and other silicon-based solar cells

[20p-C101-1] Preparation of Bifacial See-through Si Heterojunction Solar Cells

〇Makoto Konagai¹, Yukimi Ichikawa¹, Daichi Ishii¹, Ryousuke Ishikawa¹ (1.Tokyo City Univ.)

Keywords:Silicon solar cell, Heterojunction, Bifacial

We are developing bifacial see-through Si heterojunction (SHJ) solar cells with the aim of applying them to noise barriers on highways, fences on rooftops of buildings, and windows of buildings. Rib processing technology was applied to the preparation of see-through. First, small-area SHJ solar cells were prepared on a 5 cm square wafer. A bifacial SHJ cell having almost the same efficiency of 18% for both front-side irradiation and back-side irradiation has been obtained. Next, through-holes with a width of 1 mm to 2 mm were prepared between the cells. From the PL imaging measurement around the through-hole, it was found that the surface recombination of the side wall of the through-hole was suppressed sufficiently small. On the other hand, it is necessary to avoid a short circuit due to the overlap of the front and back ITO electrodes in the through-holes, and optimization of electrodes is an issue. Therefore, we analyzed the relationship between the distance between the ITO electrode and the through-hole and the photocurrent using a two-dimensional device simulator. As a result, it was found that it is possible to sufficiently collect photoexcited carriers from the light-irradiated portion even if the distance from the ITO electrode is about 1 mm. From the above, it was found that photocurrent can be sufficiently collected without depositing ITO on the entire surface of the cell.