High-Performance p-n Junction Transition Metal Dichalcogenide Photovoltaic Cells Enabled by MoOx Doping and Passivation

Koosha Nassiri Nazif; Aravindh Kumar; Jiho Hong; Nayeun Lee; Raisul Islam; Connor J McClellan; Ouri Karni; Jorik van de Groep; Tony F Heinz; Eric Pop; Mark L Brongersma; Krishna C Saraswat

doi:10.1021/acs.nanolett.1c00015

High-Performance p-n Junction Transition Metal Dichalcogenide Photovoltaic Cells Enabled by MoO_x Doping and Passivation

Nano Lett. 2021 Apr 28;21(8):3443-3450. doi: 10.1021/acs.nanolett.1c00015. Epub 2021 Apr 14.

Authors

Koosha Nassiri Nazif¹, Aravindh Kumar¹, Jiho Hong^{2

3}, Nayeun Lee^{2

3}, Raisul Islam¹, Connor J McClellan¹, Ouri Karni⁴, Jorik van de Groep^{2

5}, Tony F Heinz^{1

4}, Eric Pop^{1

3}, Mark L Brongersma^{2

3

4}, Krishna C Saraswat^{1

3}

Affiliations

¹ Department of Electrical Engineering, Stanford University, Stanford, California 94305, United States.
² Geballe Laboratory for Advanced Materials, Stanford University, Stanford, California 94305, United States.
³ Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, United States.
⁴ Department of Applied Physics, Stanford University, Stanford, California 94305, United States.
⁵ Institute of Physics, University of Amsterdam, 1098 XH Amsterdam, The Netherlands.

PMID: 33852295
DOI: 10.1021/acs.nanolett.1c00015

Abstract

Layered semiconducting transition metal dichalcogenides (TMDs) are promising materials for high-specific-power photovoltaics due to their excellent optoelectronic properties. However, in practice, contacts to TMDs have poor charge carrier selectivity, while imperfect surfaces cause recombination, leading to a low open-circuit voltage (V_OC) and therefore limited power conversion efficiency (PCE) in TMD photovoltaics. Here, we simultaneously address these fundamental issues with a simple MoO_x (x ≈ 3) surface charge-transfer doping and passivation method, applying it to multilayer tungsten disulfide (WS₂) Schottky-junction solar cells with initially near-zero V_OC. Doping and passivation turn these into lateral p-n junction photovoltaic cells with a record V_OC of 681 mV under AM 1.5G illumination, the highest among all p-n junction TMD solar cells with a practical design. The enhanced V_OC also leads to record PCE in ultrathin (<90 nm) WS₂ photovoltaics. This easily scalable doping and passivation scheme is expected to enable further advances in TMD electronics and optoelectronics.

Keywords: 2D materials; doping; molybdenum oxide; passivation; photovoltaics; transition metal dichalcogenides; tungsten disulfide.