Rear-emitter Si heterojunction solar cells with over 23% efficiency

Watahiki, Tatsuro; Furuhata, Takeo; Matsuura, T.; Shinagawa, Tomohiro; Shirayanagi, Yusuke; Morioka, Takayuki; Hayashida, Tomohiro; Yuda, Yohei; Kano, Shintaro; Sakai, Yuichi; Tokioka, Hidetada; Kusakabe, Yoshihiko; Fuchigami, Hiroyuki

doi:10.7567/apex.8.021402

Cited by 39 publications

(25 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This material has already been studied for several decades and found its way into several important applications including photovoltaic devices [1]- [8], thin-film transistors [9], and microelectromechanical systems [10]. Significant effort was put on the experimental [11]- [16] and theoretical [17] investigation of its growth process [4], [18], as well as its electrical [19]- [21] and optical properties [2], [15].…”

mentioning

confidence: 99%

“…More recently, μc-Si:H and nanocrystalline silicon oxide (μc-SiO x :H) have also been investigated for application in amorphous/crystalline silicon heterojunction (SHJ) solar cells [3], [5], [7], [8], [23], [24]. Device integration of these layers has the potential to improve further the already very high conversion efficiencies achieved to date of up to 25.1% for two-side-contacted and 25.6% for interdigitated back-contacted SHJ cells, obtained with presumably all-amorphous layers [25], [26].…”

mentioning

confidence: 99%

“…Furthermore, its higher doping efficiency and its improved transport properties [20], [27], [28] compared with a-Si:H [19], [20], [29]-its potentially lower contact resistivity in particular-could help to increase the fill factor (FF). In fact, μc-Si:H has been reported to suppress Schottky barriers that are prone to form at the interface with the adjacent transparent conductive oxides (TCO) [7], [8], [29], [30].…”

mentioning

confidence: 99%

See 2 more Smart Citations

Strategies for Doped Nanocrystalline Silicon Integration in Silicon Heterojunction Solar Cells

Seif

Descoeudres

Nogay

et al. 2016

IEEE J. Photovoltaics

View full text Add to dashboard Cite

Carrier collection in silicon heterojunction (SHJ) solar cells is usually achieved by doped amorphous silicon layers of a few nanometers, deposited at opposite sides of the crystalline silicon wafer. These layers are often defect-rich, resulting in modest doping efficiencies, parasitic optical absorption when applied at the front of solar cells, and high contact resistivities with the adjacent transparent electrodes. Their substitution by equally thin doped nanocrystalline silicon layers has often been argued to resolve these drawbacks. However, low-temperature deposition of highly crystalline doped layers of such thickness on amorphous surfaces demands sophisticated deposition engineering. In this paper, we review and discuss different strategies to facilitate the nucleation of nanocrystalline silicon layers and assess their compatibility with SHJ solar cell fabrication. We also implement the obtained layers into devices, yielding solar cells with fill factor values of over 79% and efficiencies of over 21.1%, clearly underlining the promise this material holds for SHJ solar cell applications.Index Terms-Microcrystalline silicon, nanocrystalline silicon, silicon heterojunctions (SHJs), solar cells.

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Strategies for Doped Nanocrystalline Silicon Integration in Silicon Heterojunction Solar Cells

Seif

Descoeudres

Nogay

et al. 2016

IEEE J. Photovoltaics

View full text Add to dashboard Cite

show abstract

“…Details of the cell structure are given in Ref. 5. J sc itself is not so high as the homojunction cell because of the thinner wafer (<150 lm) and UV absorption by a window layer (microcrystalline and amorphous Si).…”

Section: à3mentioning

confidence: 99%

“…4 In this structure, amorphous Si is introduced as a passivation layer and enables to achieve a high open circuit voltage (V oc ) of over 0.740 V. We have also investigated on the heterojunction Si solar cell and reached the efficiency of 23.46% with a rear emitter (RE) structure. 5 An RE Si solar cell has an emitter on the rear side of the Si substrate against the incoming sun light. This RE structure has several advantages to the front-emitter (FE) structure.…”

Section: Introductionmentioning

confidence: 99%

Analysis of short circuit current loss in rear emitter crystalline Si solar cell

Watahiki

Kobayashi

Morioka

et al. 2016

Journal of Applied Physics

Self Cite

View full text Add to dashboard Cite

Short circuit current (Jsc) loss in rear emitter crystalline Si solar cell is analyzed in detail by a 2D device simulation and compared with the experimental results. There is a significant loss in Jsc for the rear emitter n-Si solar cell with an n-type doped front surface field (FSF) when the base substrate resistivity is low. It is due to an increase in recombination in the FSF region led by a less barrier height for minority carriers with a lower substrate resistivity. The barrier height less than 0.1 eV causes large loss in Jsc. To achieve higher Jsc for the cells with FSF, the control of the doping concentration in FSF, the substrate thickness, and the barrier height for the minority carriers are important. A rear emitter heterojunction Si solar cell with an amorphous Si passivation layer shows no substrate resistivity dependence on Jsc since an amorphous Si possess a higher barrier height and a long bulk lifetime of more than a few milliseconds.

show abstract

Heterojunction solar cells with 23% efficiency onn-type epitaxial kerfless silicon wafers

Kobayashi

Watabe

Hao³

et al. 2016

Prog. Photovolt: Res. Appl.

View full text Add to dashboard Cite

We present a heterojunction (HJ) solar cell on n-type epitaxially grown kerfless crystalline-silicon with an in-housemeasured conversion efficiency of 23%. The total cell area is 243.4 cm 2 . The cell has a short-circuit current density of 39.6 mA cmÀ2 , an open-circuit voltage of 725 mV, and a fill factor of 0.799. The effect of stacking faults (SFs) is examined by current density (J) mapping measurements as well as by spectral response mapping. The J mapping images show that the localized lower J regions of the HJ solar cells are associated with recombination sites originating from SFs, independent of whether SFs are formed on the emitter or absorber side. The solar cell results and our analysis suggest that epitaxially grown wafers based on kerfless technology could be an alternative for low-cost industrial production of Si HJ solar cells.

show abstract

Rear-emitter Si heterojunction solar cells with over 23% efficiency

Cited by 39 publications

References 17 publications

Strategies for Doped Nanocrystalline Silicon Integration in Silicon Heterojunction Solar Cells

Strategies for Doped Nanocrystalline Silicon Integration in Silicon Heterojunction Solar Cells

Analysis of short circuit current loss in rear emitter crystalline Si solar cell

Heterojunction solar cells with 23% efficiency onn-type epitaxial kerfless silicon wafers

Contact Info

Product

Resources

About