High-temperature post-annealing effect on the device performance of B-doped p-type BaSi2/n-Si heterojunction solar cells grown by molecular beam epitaxy. (1st May 2023)

• Record Type: Journal Article
• Authors: Narita, Shunsuke; Aonuki, Sho; Yamashita, Yudai; Takayanagi, Kaori; Toko, Kaoru; Suemasu, Takashi
• Is Part Of: Japanese journal of applied physics. Volume 62:Number SD(2023)
• Publication Date: 2023-05-01
• Subjects: solar cell -- BaSi2 -- post anneal -- defect -- DLTS -- shunt resistance -- series resistance; Physics -- Periodicals; 621.05
• DOI: 10.35848/1347-4065/aca257
• Languages: English
• ISSNs: 0021-4922

Abstract

Astract: We fabricated B-doped p-BaSi2 /n-Si heterojunction solar cells by molecular beam epitaxy, and performed post-annealing at 1000 °C in an Ar atmosphere for various annealing durations ( t a ) in the range 15–300 s. At t a = 15 s, the conversion efficiency ( η ) under AM 1.5 G illumination was degraded unexpectedly from η = 1.96% for the as-grown sample to η = 0.8%. At t a ≥ 30 s, improvement of the open-circuit voltage ( V OC ) was obtained. V OC was increased from 0.28 V for the as-grown sample to 0.45 V at t a = 30 s, and the η reached 5.1%. Deep level transient spectroscopy measurement indicated the presence of hole traps coming from point defects near the BaSi2 /Si interface. The surface morphology remained almost unchanged at t a ≤ 60 s. However, part of the surface peeled off at t a ≥ 120 s when we separated the attached samples from each other.