Ag₂O/CsPbBr₃ bulk heterojunction

drastic contact resistance drop

In-situ formed Ag₂O clusters within single-crystal CsPbBr₃ act as interfacial electron acceptors, locally p-doping the contact region to achieve ohmic metal contacts without extrinsic dopants.

Wang, Laiyuan · Qian, Qi · Wang, Peiqi · Zhang, Ao · Wan, Zhong · Dehui, Zhang · Shuanghao, Zheng · Hassan Shah, Aamir · Zhou, Jingxuan · Wang, Yiliu · Huang, Yu D. · Duan, Xiangfeng

Nature Materials 2026

Specifications

Local hole density

{'zh': '5×10¹⁷', 'en': '5×10¹⁷'} cm⁻³

Contact resistance

{'zh': '26–70', 'en': '26–70'} Ω·cm

Two-terminal sheet conductance

{'zh': '225', 'en': '225'} µS

Advantages

Drastic contact resistance drop

Ag₂O clusters act as interfacial electron acceptors to locally p-dope the contact region, reducing Rc to 26–70 Ω·cm, more than an order of magnitude lower than undoped perovskites.

No extrinsic dopants

Silver diffusion and in-situ oxidation form Ag₂O without extrinsic dopants, preserving the perovskite's intrinsic properties.

Low-temperature process

Annealing at 80–180 °C suffices for doping, compatible with flexible substrates and temperature-sensitive devices.

Ohmic contacts achieved

The Schottky barrier is markedly thinned, approaching ohmic contacts and enabling efficient carrier injection.

Applications

• perovskite photodetectors：Reduce contact resistance to improve photodetector response speed and sensitivity.
• perovskite LEDs：Achieve efficient hole injection to enhance LED external quantum efficiency.
• perovskite solar cells：Optimize carrier extraction to reduce series resistance losses.
• flexible perovskite devices：Low-temperature process compatible with flexible substrates for high-performance flexible devices.