09

2025

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01

Design and Development of Full-Spectrum Photodetectors

Author:


In recent years, the rapidly developing optoelectronic industry has changed the world and extended into many aspects of life. Among them, photodetectors (PDs) with deep ultraviolet-visible-near-infrared full-spectrum detection response bandwidth play a key role in daily life. Typically, commercial full-spectrum PDs are mainly based on traditional semiconductor materials, such as visible-near-infrared silicon (Si) based PDs and visible-shortwave infrared indium gallium arsenide (InGaAs) based PDs. However, the aforementioned PDs require complex deposition preparation processes, and the dark current and noise signals during device operation are relatively large, making the detection performance in need of further improvement. Meanwhile, due to the high light reflection coefficient and shallow ultraviolet light penetration depth of traditional semiconductor materials, it is difficult for the prepared PDs to achieve high sensitivity detection of ultraviolet light. Currently, the most mature method for preparing deep ultraviolet-visible-infrared full-spectrum PDs is mainly based on the high integration of ultraviolet PDs and visible-infrared PDs. However, issues such as system volume, cost, and differences in response capabilities of different types of PDs hinder further commercial applications. Therefore, exploring and developing deep ultraviolet-visible-infrared high detection sensitivity full-spectrum PDs has become one of the research hotspots in the current field.

 

Research on constructing heterojunction strategies to utilize the synergistic effect of materials responsive to different wavelengths to broaden the detection range, suppress device dark current, and improve detection sensitivity has been widely reported. However, the aforementioned research mainly aims to broaden the infrared response of PDs, lacking theoretical and systematic in-depth exploration in aspects such as the interaction at the interface after constructing the heterojunction, charge transport relationships, device mechanical performance and stability, and the impact of heterojunction layer thickness on device performance. In addition, strategies that utilize fluorescent conversion materials to absorb deep ultraviolet-ultraviolet light and emit visible or infrared photons consistent with the PDs response wavelength, thereby enhancing the device's ultraviolet detection performance, have received considerable attention.

 

To achieve efficient and stable deep ultraviolet-visible-near-infrared II region full-spectrum broadband response PDs, this paper mainly conducts research in the following three aspects:
1,By doping rare earth holmium ions (Ho3+) into CsPbI3PQDs to improve the response performance in the visible light region and device stability (400-700 nm);
2,By combining near-infrared absorbing PbS quantum dots with the visible light layer to achieve visible-near-infrared II region wavelength response (400-1700 nm);

3,By doping rare earth ions (Ce3+, Yb3+, Er3+) into CsPbCI3:Cr3+PQDs to achieve efficient near-infrared (900-1700 nm) quantum cutting emission, with a fluorescence quantum efficiency of 179%. Further, constructing it as a fluorescent concentrator (LC) applied to the outer layer of the device achieves high-performance ultraviolet wavelength response (200-400 nm). Ultimately, the prepared PDs achieved full-spectrum response from 200-1700 nm, while their overall device detection performance exceeded 1012Jones, and exhibited good operational stability.

 

 
 

Research Highlights

a) Firstly, doping Ho3+into CsPbIPQDs, through the study of the optoelectronic properties of the material, it can be concluded that Ho3doping improves the3+luminescence quantum efficiency of PQDs (>>93.5%) and radiative transition rate, reduces its own lattice defects, and achieves efficient electron transport characteristics. At the same time, the ultraviolet light irradiation and thermal stability of the PQDs material have also been greatly improved.PQDs, through the study of the optoelectronic properties of the material, it can be concluded that Ho3b) The combination of PbS quantum dots withPQDs, through the study of the optoelectronic properties of the material, it can be concluded that Ho3PQDs achieved broadband light absorption from visible light to near-infrared II region (400-1700 nm); at the same time, the luminescence intensity decreased after the combination, proving that effective charge transfer was achieved between the two; further, through first-principles calculations, the accuracy of the experimental results was theoretically verified.

 

c) The preparation of CsPbClPQDs, through the study of the optoelectronic properties of the material, it can be concluded that Ho3:Cr

 

, Ce3PQDs as ultraviolet absorbing and near-infrared quantum cutting emission fluorescent conversion materials, where3+doping can reduce3+, Yb3+, Er3+the defects of CsPbCICr3+PQDs itself, improving material stability;Ce3as an intermediate energy level facilitatesthe better charge transfer from PQDs to3+YbCe3while having deep ultraviolet absorption of 4f-5d, which can broaden its overall absorption to 200 nm;as a near-infrared light emitting ion, achieving quantum cutting light emission from 900-1700 nm, which is then absorbed by the heterojunction layer. Preparing it in the concentrator improved the effective utilization of near-infrared light, achieving efficient ultraviolet response (200-400 nm).3+, Er3+d) The combination of the three achieved high sensitivity detection from 200-1700 nm, with detection responses at wavelengths of 260 nm, 460 nm, and 1550 nm reaching 3.19×as a near-infrared light emitting ion, achieving quantum cutting light emission from 900-1700 nm, which is then absorbed by the heterojunction layer. Preparing it in the concentrator improved the effective utilization of near-infrared light, achieving efficient ultraviolet response (200-400 nm).3+, Er3+Jones, 1.05×

 

Jones, and 2.23×1012Jones. At the same time, the device has high stability and cycling characteristics.1013Figure 1. (a) Response wavelength range of different types of detectors. (b) Schematic diagram of device structure. (c) Absorption and emission spectra of PbS quantum dots. (d) Energy transfer schematic of CsPbCl1012PQDs. (e) CsPbCl

PQDs concentrator, PbS and CsPbCl 3PQDs as ultraviolet absorbing and near-infrared quantum cutting emission fluorescent conversion materials, where 3+doping can reduce 3+, Yb 3+, Er 3+:Ho 3PQDs as ultraviolet absorbing and near-infrared quantum cutting emission fluorescent conversion materials, where 3+doping can reduce 3+, Yb 3+, Er 3+PQDs聚光器, PbS和CsPbCl 3:Ho 3+PQDs absorption spectrum, and CsPbCl 3PQDs as ultraviolet absorbing and near-infrared quantum cutting emission fluorescent conversion materials, where 3+doping can reduce 3+, Yb 3+, Er 3+PQDs concentrator emission spectrum.