A transparent p-type semiconductor designed via a polarizability-enhanced strongly correlated insulator oxide matrix

초록

Electron-transporting transparent conducting oxides (TCOs) are a commercial reality, however, hole-transporting counterparts are far more challenging because of limited material design. Here, we propose a strategy for enhancing the hole conductivity without deteriorating the band gap (E<inf>g</inf>) and workfunction (Φ) by Cu incorporation in a strongly correlated NiWO<inf>4</inf> insulator. The optimal Cu-doped NiWO<inf>4</inf> (Cu<inf>0.185</inf>Ni<inf>0.815</inf>WO<inf>4</inf>) exhibits a resistivity reduction of ∼109 times versus NiWO<inf>4</inf> as well as band-like charge transport with the hole mobility approaching 7 cm2 V−1 s−1 at 200 K, a deep Φ of 5.77 eV, and E<inf>g</inf> of 2.8 eV. Experimental and theoretical data reveal that the strength of the electron correlation in NiWO<inf>4</inf> is unaffected by Cu incorporation, while the promoted polarizability weakens electron-phonon coupling, promoting the formation of large polarons. Quantum dot light-emitting and oxide p/n junction devices incorporating Cu<inf>0.185</inf>Ni<inf>0.815</inf>WO<inf>4</inf> exhibit remarkable performances, demonstrating that our approach can be deployed to discover new p-type TCOs. © 2024 The Royal Society of Chemistry.