Titanium oxide electron-selective layers for contact passivation of thin-film crystalline silicon solar cells

Liu, Yi; Chen, Yusi; LaFehr, David T.; Su, Yen Chen; Huo, Yijie; Kang, Yangsen; Deng, Huiyang; Jia, Jieyang; Zhao, Li; Yuan, Mengyang; Lyu, Zheng; DeWitt, Daniel; Vilgalys, Max A.; Zang, Kai; Chen, Xiaochi; Lu, Ching-Ying; Kamins, Theodore I.; Harris, James S.

doi:10.1117/12.2213540

Cited by 3 publications

(4 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, to avoid the nonconformal coating of metals and complete oxidation of Al, a few nanometers can be adequate . A similar methodology to extract J 0,metal have been previously reported in the literature …”

Section: Characterization Of Atom Test Structuresmentioning

confidence: 97%

Passivating electron‐selective contacts for silicon solar cells based on an a‐Si:H/TiO_x stack and a low work function metal

Cho

Melskens

Debucquoy

et al. 2018

Progress in Photovoltaics

View full text Add to dashboard Cite

In this work, the ATOM (intrinsic a-Si:H/TiO x /low work function metal) structure is investigated to realize high-performance passivating electron-selective contacts for crystalline silicon solar cells. The absence of a highly doped Si region in this contact structure is meant to reduce the optoelectrical losses. We show that a low contact resistivity (ρ c ) can be obtained by the combined effect of a low work function metal, such as calcium (Φ 2.9 eV), and Fermi-level depinning in the metal-insulator-semiconductor contact structure (where in our case TiO x acts as the insulator on the intrinsic a-Si:H passivating layer). TiO x grown by ALD is effective to achieve not only a low ρ c but also good passivation properties. As an electron contact in silicon heterojunction solar cells, inserting interfacial TiO x at the i-a-Si:H/Ca interface significantly enhances the solar cell conversion efficiency. Consequently, the champion solar cell with the ATOM contact achieves a V OC of 711 mV, FF of 72.9%, J SC of 35.1 mA/cm 2 , and an efficiency of 18.2%. The achievement of a high V OC and reasonable FF without the need for a highly doped Si layer serves as a valuable proof of concept for future developments on passivating electron-selective contacts using this structure.

show abstract

Section: Characterization Of Atom Test Structuresmentioning

confidence: 97%

Passivating electron‐selective contacts for silicon solar cells based on an a‐Si:H/TiO_x stack and a low work function metal

Cho

Melskens

Debucquoy

et al. 2018

Progress in Photovoltaics

View full text Add to dashboard Cite

show abstract

“…When the solar cell is ultrathin, the carrier selectivity becomes predominantly limited by the recombination of minority carriers at the contacts. 13 It has been shown that the minority carrier recombination losses at the metal/Si interface significantly reduce the selectivity of the contacts, resulting in a degradation of the open-circuit voltage. 17 Figure 1a shows all dominant recombination mechanisms during the operation of a typical p−n junction solar cell.…”

Section: ■ Introductionmentioning

confidence: 99%

“…The performance of ultrathin c-Si solar cells is constrained not only by the limited light absorption but also by the selectivity of the contacts − to reach the theoretical efficiency of silicon solar cells. , Selectivity of the contact in the context of PVs means the ability of a contact to pass one type of carrier and block the other type. Typically, the formation of a p–n junction provides the required carrier selectivity by creating the built-in electric field.…”

Section: Introductionmentioning

confidence: 99%

“…Typically, the formation of a p–n junction provides the required carrier selectivity by creating the built-in electric field. When the solar cell is ultrathin, the carrier selectivity becomes predominantly limited by the recombination of minority carriers at the contacts . It has been shown that the minority carrier recombination losses at the metal/Si interface significantly reduce the selectivity of the contacts, resulting in a degradation of the open-circuit voltage …”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Contact Selectivity Engineering in a 2 μm Thick Ultrathin c-Si Solar Cell Using Transition-Metal Oxides Achieving an Efficiency of 10.8%

Xue

Islam

Meng

et al. 2017

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

In this paper, the integration of metal oxides as carrier-selective contacts for ultrathin crystalline silicon (c-Si) solar cells is demonstrated which results in an ∼13% relative improvement in efficiency. The improvement in efficiency originates from the suppression of the contact recombination current due to the band offset asymmetry of these oxides with Si. First, an ultrathin c-Si solar cell having a total thickness of 2 μm is shown to have >10% efficiency without any light-trapping scheme. This is achieved by the integration of nickel oxide (NiO) as a hole-selective contact interlayer material, which has a low valence band offset and high conduction band offset with Si. Second, we show a champion cell efficiency of 10.8% with the additional integration of titanium oxide (TiO), a well-known material for an electron-selective contact interlayer. Key parameters including V and J also show different degrees of enhancement if single (NiO only) or double (both NiO and TiO) carrier-selective contacts are integrated. The fabrication process for TiO and NiO layer integration is scalable and shows good compatibility with the device.

show abstract

Evidence of TiOx reduction at the SiOx/TiOx interface of passivating electron-selective contacts

Cho¹,

Debucquoy²,

Payo³

et al. 2018

AIP Conference Proceedings

View full text Add to dashboard Cite

Titanium oxide electron-selective layers for contact passivation of thin-film crystalline silicon solar cells

Cited by 3 publications

References 33 publications

Passivating electron‐selective contacts for silicon solar cells based on an a‐Si:H/TiO_x stack and a low work function metal

Passivating electron‐selective contacts for silicon solar cells based on an a‐Si:H/TiO_x stack and a low work function metal

Contact Selectivity Engineering in a 2 μm Thick Ultrathin c-Si Solar Cell Using Transition-Metal Oxides Achieving an Efficiency of 10.8%

Evidence of TiOx reduction at the SiOx/TiOx interface of passivating electron-selective contacts

Contact Info

Product

Resources

About

Titanium oxide electron-selective layers for contact passivation of thin-film crystalline silicon solar cells

Cited by 3 publications

References 33 publications

Passivating electron‐selective contacts for silicon solar cells based on an a‐Si:H/TiOx stack and a low work function metal

Passivating electron‐selective contacts for silicon solar cells based on an a‐Si:H/TiOx stack and a low work function metal

Contact Selectivity Engineering in a 2 μm Thick Ultrathin c-Si Solar Cell Using Transition-Metal Oxides Achieving an Efficiency of 10.8%

Evidence of TiOx reduction at the SiOx/TiOx interface of passivating electron-selective contacts

Contact Info

Product

Resources

About

Passivating electron‐selective contacts for silicon solar cells based on an a‐Si:H/TiO_x stack and a low work function metal

Passivating electron‐selective contacts for silicon solar cells based on an a‐Si:H/TiO_x stack and a low work function metal