ScholarWorks@성균관대학교

초록

Minimizing contact resistance between metal electrodes and perovskites remains a critical challenge in developing perovskite-based electronic and optoelectronic devices. Despite extensive experimental and theoretical efforts to minimize the contact resistance, atomic-level insights into metal-perovskite interfaces remain insufficiently understood. In this paper, we investigate the electronic and transport properties of 2D hybrid organic-inorganic perovskites, specifically (BA)2PbBr4 and (PEA)2PbBr4, which consist of monolayer bromide perovskite layers with different organic spacer molecules: n-butylammonium (BA) and phenylethylammonium (PEA) cations. We provide a comprehensive analysis of the Au/perovskites interface, considering two contact configurations, i.e., top-contact and edge-contact. We perform first-principles calculations and use the nonequilibrium Green's function formalism to calculate the transport characteristics. We find that a Schottky barrier forms in the top-contact configuration, but the edge-contact configuration shows ohmic behavior for both Au/(BA)2PbBr4 and Au/(PEA)2PbBr4. The edge-contact configuration also enables highly efficient charge injection with a negligible interfacial tunneling barrier due to Au-induced midgap states. For the top contact configuration, Au/(PEA)2PbBr4 shows better transport behavior compared to (BA)2PbBr4, which is attributed to its lower tunneling barrier and higher density of metal-induced midgap states. This work provides theoretical guidelines for designing low-resistance metal-2D hybrid perovskite contacts.

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