Mn<sup>2+</sup>-Doped CsPbBr<sub>2</sub>I Quantum Dots Photosensitive Films for High-Performance Photodetectors
The variable bandgap and high absorption coefficient of all-inorganic halide perovskite quantum dots (QDs), particularly CsPbBr<sub>2</sub>I make them highly promising for photodetector applications. However, their high defect density and poor stability limit their performance. To overco...
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| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-03-01
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| Series: | Nanomaterials |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2079-4991/15/6/444 |
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| Summary: | The variable bandgap and high absorption coefficient of all-inorganic halide perovskite quantum dots (QDs), particularly CsPbBr<sub>2</sub>I make them highly promising for photodetector applications. However, their high defect density and poor stability limit their performance. To overcome these problems, Mn<sup>2+</sup>-doped CsPbBr<sub>2</sub>I QDs with varying concentrations were synthesized via the one-pot method in this work. By replacing Pb<sup>2+</sup> ions, moderate Mn<sup>2+</sup> doping caused lattice contraction and improved crystallinity. At the same time, Mn<sup>2+</sup>-doping effectively passivated surface defects, reducing the defect density by 33%, and suppressed non-radiative recombination, thereby improving photoluminescence (PL) intensity and carrier mobility. The optimized Mn:CsPbBr<sub>2</sub>I QDs-based photodetector exhibited superior performance, with a dark current of 1.19 × 10<sup>−10</sup> A, a photocurrent of 1.29 × 10<sup>−5</sup> A, a responsivity (<i>R</i>) of 0.83 A/W, a specific detectivity (<i>D</i>*) of 3.91 × 10<sup>12</sup> Jones, an on/off ratio up to 10<sup>5</sup>, and the response time reduced to less than 10 ms, all outperforming undoped CsPbBr<sub>2</sub>I QDs devices. Stability tests demonstrated enhanced durability, retaining 80% of the initial photocurrent after 200 s of cycling (compared to 50% for undoped devices) and stable operation over 20 days. This work offers a workable strategy for rational doping and structural optimization in the construction of high-performance perovskite optoelectronic devices. |
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| ISSN: | 2079-4991 |