Hydrogenated amorphous silicon based surface passivation of c‐Si at high deposition temperature and rate

Abstract

Low substrate temperature during deposition of a‐Si:H is considered a necessary condition to reach excellent surface passivation of c‐Si wafers, such as a hydrogen‐rich and atomically abrupt a‐Si:H/c‐Si interface forms. From a comparison between surface passivation levels achieved by different deposition methods, delivering a broad range of a‐Si:H growth rates, we show that a high a‐Si:H deposition rate (∼3 nm/s) is crucial in achieving an excellent level of surface passivation at high deposition temperatures (>425 °C) compatible with emerging post‐deposition thermal treatments of solar cells. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Status and prospects of Al2O3-based surface passivation schemes for silicon solar cells

“…a-Si:H leads to excellent passivation properties with S eff as low as 2 cm/s. [70][71][72][73][74][75] The growth related material properties of PECVD a-Si:H have been studied in depth for applications such as thin film Si solar cells. [76][77][78][79][80] This knowledge is also useful for the optimization and understanding of the a-Si:H properties for crystalline Si technology.…”

Electrical Interface Characterization of Ultrathin Amorphous Silicon Layers on Crystalline Silicon

“…[2,47,48] The bandgap of amorphous silicon can be changed by introducing hydrogen, as shown in earlier work, [2,43,49] and herewith the band offsets. Furthermore, hydrogen saturates dangling silicon bonds [25] and reduces therefore the density of trap states within the bandgap. [46] The study of samples with varying hydrogen content is therefore a promising approach toward a better understanding of the role of hydrogen in amorphous silicon.…”

“…Earlier work on a-Si/c-Si systems often focused on the importance of annealing temperatures during or after deposition, [3,[23][24][25] which affect structural and electrical properties of the samples. [3,17,[24][25][26][27] The most common technique for the sample and large-scale preparation of solar cells composed of amorphous and crystalline silicon is plasmaenhanced chemical vapor deposition (PECVD), [22,28,29] which allows large-area deposition at low temperatures and high deposition rates. [30] However, when using PECVD, complex plasma chemistry has to be considered as a mixture of multiple gases is used.…”

Rational Approach for High‐Efficiency Dopant‐Free Solar Cells Characterized with Key Parameters

“…[19][20][21][22] The use of hydrogenrich amorphous silicon (a-Si:H) deposited by PECVD in solar cells has emerged as a promising approach to enhance efficiency by passivating defects and achieving high open-circuit voltage. [23,24] Heterojunctions with intrinsic thin-layer (HIT) solar cells, which utilize thin layers of intrinsic and doped a-Si:H on c-Si wafers, exemplify this approach. HIT solar cells exhibit the highest reported efficiencies among c-Si solar cells.…”