Tailoring Hole-Blocking Layers Enables a Versatile Approach for Fast Photomultiplication-Type Organic Photodetectors
Research output: Contribution to journal › Research article › Contributed › peer-review
Contributors
Abstract
Organic photodetectors (OPDs) are promising for various applications due to their cost-effectiveness in fabrication, flexibility, and tunable response to specific wavelengths. Their excellent sensitivity enables multiple applications in imaging, healthcare, and security monitoring. Notably, photomultiplication-type organic photodetectors (PM-OPDs) offer distinct advantages due to their internal amplification mechanism. In this work, a strategy is presented for employing two hole-blocking layers (HBLs) to improve the photodetection capabilities of PM-OPDs. A systematic exploration of the HBL material combination reveals the importance of shallow lowest unoccupied molecular orbital (LUMO) and deep highest occupied molecular orbital (HOMO) levels for optimal performance. Utilizing HBLs with deep HOMO levels, HAT(CN)6 and C60, leads to enhanced hole accumulation, resulting in a distinct photomultiplication effect. Optimized devices exhibit an impressive external quantum efficiency (EQE) surpassing 1290%, shot-noise limited specific detectivity of 1.7 × 1012 Jones (2.4 × 1011 Jones based on noise measurements), and a rapid cutoff frequency exceeding 40 kHz, representing a significant advancement in PM-OPD capabilities. Moreover, this device architecture surpasses current limitations by ensuring compatibility with various photoactive layers with balanced donor-acceptor stoichiometry. Our results confirm this universal approach, which enables high-gain PM-OPDs across spectral ranges while maintaining fast response speeds.
Details
| Original language | English |
|---|---|
| Article number | 2424456 |
| Number of pages | 11 |
| Journal | Advanced functional materials |
| Volume | 35 |
| Issue number | 29 |
| Publication status | Published - 17 Jul 2025 |
| Peer-reviewed | Yes |
Keywords
ASJC Scopus subject areas
Keywords
- blocking layers, organic photodetectors, photomultiplication, response speed