INVESTIGATION OF SCREEN-PRINTED AND EVAPORATED METAL CONTACTS ON BORON IMPLANTED EMITTER

2021-8-27
Özmen, Ege
Due to advantages in device manufacturing and the low cost of ownership, crystalline silicon (c-Si) solar cells fabricated on p-type wafers continue to dominate the photovoltaic (PV) market. Studies on n-type Czochralski (CZ) substrates have shown that they are more desirable for terrestrial applications than p-type substrates due to superior material and performance advantages such as higher minority carrier lifetime and easier surface passivation, absence of light-induced degradation (LID), and low sensitivity to metallic impurities. With these advantages, n-type CZ-based c-Si solar cells hold great potential in the future PV industry. However, various difficulties in device processing and higher wafer cost are still the major obstacles in penetrating the n-type solar cells into the commercial market. In dealing with these difficulties, new processes like ion implantation are being considered to replace the existing ones to simplify the process conditions and lower the cost. This thesis aims to optimize the activation temperature and duration of the boron implanted silicon with metal contacts fabricated by screen printing and e-beam evaporation. In order to understand the uniformity of the ion implantation, sheet resistance measurements were carried out. Al2O3/SiNx stack was used for passivation and ARC. Also, deeper boron concentration leads to lower contact resistivity is tested with e-beam evaporated and screen-printed metal contacts with contact resistivity values measured using Transmission Line Measurement (TLM). We have shown that successful metal contact to ion-implanted Si can be formed using both techniques. This thesis presents excessive process information and results for the screen-printed and e-beam evaporated samples onto the boron implanted silicon.

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Citation Formats
E. Özmen, “INVESTIGATION OF SCREEN-PRINTED AND EVAPORATED METAL CONTACTS ON BORON IMPLANTED EMITTER,” M.S. - Master of Science, Middle East Technical University, 2021.