Krishna Saraswat, Doctoral Dissertation Advisor (AC)
High-Performance p-n Junction Transition Metal Dichalcogenide Photovoltaic Cells Enabled by MoOx Doping and Passivation.
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 (VOC) and therefore limited power conversion efficiency (PCE) in TMD photovoltaics. Here, we simultaneously address these fundamental issues with a simple MoOx (x 3) surface charge-transfer doping and passivation method, applying it to multilayer tungsten disulfide (WS2) Schottky-junction solar cells with initially near-zero VOC. Doping and passivation turn these into lateral p-n junction photovoltaic cells with a record VOC of 681 mV under AM 1.5G illumination, the highest among all p-n junction TMD solar cells with a practical design. The enhanced VOC 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.
View details for DOI 10.1021/acs.nanolett.1c00015
View details for PubMedID 33852295
Doped WS2 transistors with large on-off ratio and high on-current
View details for Web of Science ID 000615719100013
- On the limit of defect doping in transition metal oxides JOURNAL OF VACUUM SCIENCE & TECHNOLOGY A 2019; 37 (2)
- Towards high V-oc, thin film, homojunction WS2 solar cells for energy harvesting applications SPIE-INT SOC OPTICAL ENGINEERING. 2019