High Responsivity and External Quantum Efficiency Photodetectors Based on Solution-Processed Ni-Doped CuO Films

Area of Science:

• Materials Science
• Optoelectronics
• Semiconductor Physics

Background:

• Photodetectors based on p-type metal oxides present challenges in optoelectronic applications.
• Improving performance and expanding detection range are key research areas.

Purpose of the Study:

• To investigate the effect of nickel (Ni) doping on the performance of copper oxide (Cu_1-xNi_xO) photodetectors.
• To explore Ni doping as a method to enhance photodetector characteristics.

Main Methods:

• High-quality Cu_1-xNi_xO (x = 0, 0.2, 0.4) films were fabricated using a solution process.
• The crystal quality, morphology, and grain size were modulated by varying Ni doping concentrations.
• Photocurrent, responsivity, and external quantum efficiency were measured under laser illumination.

Main Results:

• Nickel doping effectively modulated the crystal quality, morphology, and grain size of Cu_1-xNi_xO films.
• The Cu_0.8Ni_0.2O photodetector exhibited the highest photocurrent (6 × 10^-7 A) at 635 nm.
• This photodetector achieved high responsivity (26.46 A/W) and external quantum efficiency (5176%).
• The Cu_0.8Ni_0.2O photodetector demonstrated optimal response in the near-infrared region due to a high absorption coefficient.

Conclusions:

• The Cu_0.8Ni_0.2O photodetector shows enhanced performance attributed to high photoconductivity, low surface states, and high crystallization.
• Ni doping provides an effective strategy for fabricating high-performance, wide-detection range p-type metal oxide photodetectors.