High efficiency thin film silicon solar cells prepared by zone-melting recrystallization

Abstract

A new type of silicon solar cell is demonstrated using chemical vapor deposited silicon thin films on a silicon dioxide layer. In order to improve the crystal quality of the thin films, zone-melting recrystallization (ZMR) is applied and grain boundaries of polycrystalline Si films are passivated with H+. It is found that H+ passivation is quite effective for thin film Si solar cells and ZMR conditions to provide dominant (100) orientation is essential for achieving higher conversion efficiency. This (100) nature is also favorable for making effective light confinement scheme with pyramidal textured surface using anisotropic chemical etching. The conversion efficiency as high as 14.2% for a practical size of 10×10 cm2 is achieved. This is the highest for large area thin film polycrystalline Si solar cells so far.

Farklı Üretim Parametrelerinin Katı Faz Kristalizasyon (SPC) Tekniği Kullanılarak Üretilen Polikristal Silisyum İnce Filmlerin Kalitesi Üzerine Etkileri

“…Bundan başka, tanecik sınır rekombinasyonlarının etkisini düşürmek için tanecik büyüklükleri film kalınlığından daha büyük olmalıdır [9]. Optimum poly-Si ince film malzemelerin kalınlığı 1-4µm arasında olduğuna göre iyi bir poly-Si filmin ortalama tanecik büyüklüğü ≥2µm olmalıdır [10,11]. Poly-Si ince film malzemelerin üretimi için farklı kristalizasyon teknikleri kullanılabilir [5,7]: Bölgesel eritme kristalizasyonu (zone melting crystallization -ZMC), lazer indüklemeli kristalizasyon (laser induced crystallization -LIC), katı faz kristalizasyonu (solid phase crystallization -SPC) ve metal indüklemeli kristalizasyon (metal induced crystallization -MIC) bunların başlıcalarıdır.…”

High-throughput zone-melting recrystallization for crystalline silicon thin-film solar cells

“…Our aim was to evaluate the influence of melting speed not only on crystal structure and defect density, but also on the more important parameter, namely solar cell performance. Investigations on this topic were already done in the beginning 1990s by a group at Mitsubishi Corp. [13][14][15], but focussed on comparatively thin seeding layers. Since very thin seeding layers are not compatible with recrystallized CSiTF solar cells due to the surface roughness, usually some micrometer large, of lowcost substrates, additional experiments were needed.…”

Optimization of material structure of ploy-Si thin film based on Al induced crystallization

“…Recently, a CVD poly-Si thin film cell with light transformation efficiency of 16% was reported by Japan's Mitsubishi Corporation [1,2] . However, the very high production costs also greatly restricted the poly-Si thin film cell technology to a wider range of applications [3] .…”