Abstract
Photodiodes based on two-dimensional semiconductors are of potential use in the development of optoelectronic devices, but their photovoltaic efficiency is limited by strong Fermi level pinning at metal–semiconductor contacts. Typical metal–interlayer–semiconductor contacts can address this issue, but can also lead to an increase in series resistance. Here we report a conductive-bridge interlayer contact that offers both Fermi level depinning and low resistance. We create an oxide interlayer that decouples the metal and semiconductor, while embedded gold nanoclusters in the interlayer act as conductive paths that facilitate efficient charge transport. Using these contacts, we fabricate a tungsten disulfide (WS2) photodiode with a photoresponsivity of 0.29 A W−1, linear dynamic range of 122 dB and power conversion efficiency of 9.9%. Our approach also provides a platform for probing photocarrier dynamics, and we find that contact recombination substantially affects photovoltaic performance. In addition, we illustrate the potential of using photodiodes with these conductive-bridge interlayer contacts as full-colour two- and three-dimensional imagers.
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Data availability
The data that support the plots within this paper and other findings of this study are available from the corresponding authors upon reasonable request.
Code availability
Any codes used in this study are available from the corresponding authors upon reasonable request.
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Acknowledgements
We acknowledge financial support from the Korea Institute of Science and Technology (KIST) Institution Program (grant nos. 2E33542, 2E33423 and 2V10330-24-P039), KU-KIST Graduate School of Converging Science and Technology project, the Institute for Information & Communications Technology Promotion (grant no. IITP-2023-RS-00258639), the National Research Foundation of Korea (grant nos. 2023R1A2C2003985 and RS-2024-00461204), the Korea Institute of Planning and Evaluation for Technology in Food, Agriculture and Forestry (grant no. 421025043SB010), the Korea Creative Content Agency (grant nos. R2020040080 and RS-2020-KC000685) and Korean National Police Agency (grant no. PR08-04-000-23). Kihyun Lee and K.K. acknowledge the support from the Basic Science Research Program of the National Research Foundation of Korea (grant no. NRF-2017R1A5A1014862) and by the Institute for Basic Science (grant no. IBS-R026-D1). We acknowledge J.Y. Kim from the Advanced Analysis & Data Center at KIST for support with electron-beam lithography. M.-C.P. wishes to thank CEO R. Minho and artist PSY, P. Jaisang of PNATION, for their invaluable assistance in facilitating the three-dimensional image visualization.
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J.J., J.P.H. and S.-J.K. contributed equally. D.K.H. and J.J. conceived the idea and designed the experiments. J.J. and J.P.H. fabricated and characterized the devices. J.J. performed the first-principles and numerical drift-diffusion calculations. S.-J.K., J.-H.K. and M.-C.P. designed and set up the imaging system. J.H. and Y.J.S. performed the CAFM and KPFM measurements. Kihyun Lee and K.K. performed the HR-STEM and EDS measurements. W.K. and S.P. performed the XPS analysis. Kimoon Lee supplied Cl–SnSe2 single crystals. T.T. and K.W. provided the h-BN crystals. J.A., B.-S.Y., S.J., H.W.K, S.K.Y., H.B., S.M., H.J.K., S.A.L., J.W.S., G.W. and J.-H.K. provided feedback throughout the experiments and data analysis. J.J., J.P.H. and S.-J.K. cowrote the manuscript with input from all authors. D.K.H. and M.-C.P. supervised the project. All the authors discussed the results and approved the manuscript.
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3D reconstruction process.
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Jang, J., Hong, J.P., Kim, SJ. et al. Conductive-bridge interlayer contacts for two-dimensional optoelectronic devices. Nat Electron 8, 298–308 (2025). https://doi.org/10.1038/s41928-025-01339-9
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DOI: https://doi.org/10.1038/s41928-025-01339-9
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