Silicon Heterojunction Solar Cells with p-Type Silicon Carbon Window Layer

Abstract

Boron-doped hydrogenated amorphous silicon carbide (a-SiC:H) thin films are deposited using high frequency 27.12 MHz plasma enhanced chemical vapor deposition system as a window layer of silicon heterojunction (SHJ) solar cells. The CH4 gas flow rate is varied to deposit various a-SiC:H films, and the optical and electrical properties are investigated. The experimental results show that at the CH4 flow rate of 40 sccm the a-SiC:H has a high band gap of 2.1 eV and reduced absorption coefficients in the whole wavelength region, but the electrical conductivity deteriorates. The technology computer aided design simulation for SHJ devices reveal the band discontinuity at i/p interface when the a-SiC:H films are used. For fabricated SHJ solar cell performance, the highest conversion efficiency of 22.14%, which is 0.33% abs higher than that of conventional hydrogenated amorphous silicon window layer, can be obtained when the intermediate band gap (2 eV) a-SiC:H window layer is used.

Synthesis of Boron-Doped Silicon Film Using Hot Wire Chemical Vapor Deposition Technique

“…Sapphire is chosen as a robust substrate and Ni-W is chosen as a flexible substrate. A range of experiments were conducted by varying the growth conditions to optimize the crystalline quality of silicon film with an intention to use the film in a solar cell [9,10]. Thin-film solar cells of p-i-n structure have i-layer as the light absorber and p-type layer as a window.…”

Power generation characteristics of Si PV cell under extremely high-intensity near-infrared light irradiation

“…The cell temperature begins to rise with irradiation, and the temperature rise was higher in the order of 1) 730 nm, 2) 850 nm and 3) 940 nm at 10-sun power level, sunlight at 4) 2-sun and 5) 1-sun power level, 6) 730 nm, 7) 850 nm and 8) 940 nm at 1-sun power level. This indicates that light absorption coefficient is higher in the order of 1) 730 nm, 2) 850 nm and 3) 940 nm for near-infrared light, and absorption for sunlight is relatively higher than those near-infrared light [20,21]. The temperature increased when irradiated at 10-sun power level ranged from about 15-21 degrees from room temperature of 25-26℃.…”

π-Conjugated Polymers and Their Application in Organic and Hybrid Organic-Silicon Solar Cells

“…P-type a-Si:H is often used at the emitter region in a front contact structure working as both the emitter layer and HTL. As impressive as these SHJs are, their practical use is limited by the complexity in fabrication processes, high deposition temperatures of (p)-a-Si:H, and the expenses of the state-of-the-art PECVD method, which increases costs [126]. Additionally, the well-known absorption inability of blue light by a-Si:H on the front side [7,[126][127] and the large resistivity at the ITO/a-Si:H interface which results in electrical losses [128], hinders the development of SHJs incorporating (p)-a-Si:H. Ideally, a very thin emitter layer should have low light absorption, low resistivity, and high conductivity.…”

“…As impressive as these SHJs are, their practical use is limited by the complexity in fabrication processes, high deposition temperatures of (p)-a-Si:H, and the expenses of the state-of-the-art PECVD method, which increases costs [126]. Additionally, the well-known absorption inability of blue light by a-Si:H on the front side [7,[126][127] and the large resistivity at the ITO/a-Si:H interface which results in electrical losses [128], hinders the development of SHJs incorporating (p)-a-Si:H. Ideally, a very thin emitter layer should have low light absorption, low resistivity, and high conductivity. Alternatives such as using p-doped microcrystalline silicon thin-film emitter (p-(𝜇c-Si:H) [129] and p-type silicon carbon (p-(a-SiC:H) emitter layer [126] in place of (p) a-Si:H have been…”

“…As impressive as these SHJs are, their practical use is limited by the complexity in fabrication processes, high deposition temperatures of (p)-a-Si:H, and the expenses of the state-of-the-art PECVD method, which increases costs [126]. Additionally, the wellknown absorption inability of blue light by a-Si:H on the front side [7,126,127] and the large resistivity at the ITO/a-Si:H interface which results in electrical losses [128], hinders the development of SHJs incorporating (p)-a-Si:H. Ideally, a very thin emitter layer should have low light absorption, low resistivity, and high conductivity. Alternatives such as using p-doped microcrystalline silicon thin-film emitter (p-(µc-Si:H) [129] and p-type silicon carbon (p-(a-SiC:H) emitter layer [126] in place of (p) a-Si:H have been developed but still lack the cutting edge due to the deposition of the layers using the complex and expensive PECVD technique.…”