scholarly journals Inverted ternary OPD based on PEIE

2021 ◽  
Author(s):  
Tao An ◽  
Suiyang Liu
Keyword(s):  
Buffer Layer ◽  
Quantum Efficiency ◽  
Active Layer ◽  
Broad Spectrum ◽  
External Quantum Efficiency ◽  
Optical Power ◽  
Organic Photodetector ◽  
Cathode Buffer Layer ◽  
Diode Mode ◽  
Conventional Device

Abstract This paper proposes an inverted ternary organic photodetector (OPD), whose structure is ITO/PEIE/PC61BM/P3HT:PCPDTBT/MoO3 /Al. The use of PEIE as the cathode buffer layer avoids the influence of acidic PEDOT:PSS on the surface and life of the conventional device . The preparation of the ternary active layer ensures the photoelectric characteristics of the device in the visible-infrared broad spectrum range. In this experiment, the effect of PEIE thickness on the working mode of the device was studied by changing the concentration of the spin-coated PEIE solution. Finally, when the solution of PEIE is less than 0.45wt%, the device works in the diode mode, on the contrary, it works in the photoconductive mode. And under 550nm illumination (optical power 4.02mW/cm2) , the device achieves a responsivity of 1.64A/W and an external quantum efficiency of 370%.

Effective film surface treatment for improving external quantum efficiency of photomultiplication type organic photodetector

2021 ◽  
pp. 095400832110214
Author(s):  
Zheng Xiao ◽  
Haitao Xu ◽  
Wenyue Liang ◽  
Binfang Wu ◽  
Yufeng Shi ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
Active Layer ◽  
External Quantum Efficiency ◽  
Film Surface ◽  
Electrical Performance ◽  
Hole Injection ◽  
Light Illumination ◽  
Methanol Treatment ◽  
Organic Photodetector ◽  
Response Current

A simple yet effective method based on methanol treatment is proposed to enhance the external quantum efficiency (EQE) of the photomultiplication type organic photodetector with a structure of Glass/ITO/PEDOT:PSS/P3H:PC71BM (100:1, wt./wt.)/Al. By modifying the PEDOT:PSS film surface with methanol, the EQE of photodetector significantly improved within a broad wavelength range of 300–700 nm. The maximum EQE of 25300% occurs at the wavelength of 350 nm in the methanol-treated device under −9 V bias, which more than doubles that (11500%) of the device without treatment. In addition, as a result of the methanol treatment, the detectivity of the device improved from 3.72 × 1012 to 7.24 × 1012 Jones at −9 V under 350 nm light illumination. The large improvement is attributed to the fact that the methanol treatment can improve the electrical performance of the PEDOT:PSS by removing the insulator PSS within the film and also result in PC71BM aggregations in the active layer. The latter can enhance the tunneling hole injection by the intensified energy-level bending, which is induced by both the trapped electrons in these aggregations and accumulated ones near Al electrode. As a result, the modification of both the PEDOT:PSS layer and the active layer increases the response current, resulting in the EQE improvement.

N-face GaN substrate roughening for improved performance GaN-on-GaN LED

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ezzah Azimah Alias ◽  
Muhammad Esmed Alif Samsudin ◽  
Steven DenBaars ◽  
James Speck ◽  
Shuji Nakamura ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Light Emitting Diode ◽  
Optical Power ◽  
Ammonium Hydroxide ◽  
Content Type ◽  
Light Emitting ◽  
Gan Led ◽  
Improved Performance ◽  
Substrate Roughening

Purpose This study aims to focus on roughening N-face (backside) GaN substrate prior to GaN-on-GaN light-emitting diode (LED) growth as an attempt to improve the LED performance. Design/methodology/approach The N-face of GaN substrate was roughened by three different etchants; ammonium hydroxide (NH4OH), a mixture of NH4OH and H2O2 (NH4OH: H2O2) and potassium hydroxide (KOH). Hexagonal pyramids were successfully formed on the surface when the substrate was subjected to the etching in all cases. Findings Under 30 min of etching, the highest density of pyramids was obtained by NH4OH: H2O2 etching, which was 5 × 109 cm–2. The density by KOH and NH4OH etchings was 3.6 × 109 and 5 × 108 cm–2, respectively. At standard operation of current density at 20 A/cm2, the optical power and external quantum efficiency of the LED on the roughened GaN substrate by NH4OH: H2O2 were 12.3 mW and 22%, respectively, which are higher than its counterparts. Originality/value This study demonstrated NH4OH: H2O2 is a new etchant for roughening the N-face GaN substrate. The results showed that such etchant increased the density of the pyramids on the N-face GaN substrate, which subsequently resulted in higher optical power and external quantum efficiency to the LED as compared to KOH and NH4OH.

scholarly journals Carbon Nanotube Film/Silicon Heterojunction Photodetector for New Cutting-Edge Technological Devices

2021 ◽  
Vol 11 (2) ◽  
pp. 606
Author(s):  
Mattia Scagliotti ◽  
Matteo Salvato ◽  
Federico Frezza ◽  
Daniele Catone ◽  
Lorenzo Di Mario ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Linear Response ◽  
Optical Power ◽  
Single Walled Carbon Nanotubes ◽  
The Core ◽  
Light Absorber ◽  
Walled Carbon Nanotubes

Photodetector (PD) devices based on carbon nanotube/n-silicon heterojunction (NSH) have been realized, with a linear response in a large optical power range, proving competitive performances with respect to a recent nanostructure-based detector and those currently available on the market. The core of these devices is a thin semi-transparent and conductive single-walled carbon nanotubes film with a multitask role: junction element, light absorber and transmitter, photocarrier transporting layer, and charge collector. The PD exhibits rise times of some nanoseconds, detecting light from ultraviolet (240 nm) to infrared (1600 nm), and external quantum efficiency reaching 300% in the VIS spectra region.

Visible-Blind Ultraviolet Narrowband Photomultiplication-Type Organic Photodetector with an Ultrahigh External Quantum Efficiency over 1000000%

2021 ◽  
Author(s):  
Dechao Guo ◽  
Liqing Yang ◽  
Jingcheng Zhao ◽  
Ji Li ◽  
Guo He ◽  
...  
Keyword(s):  
Visible Light ◽  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
High Performance ◽  
Infrared Light ◽  
Organic P ◽  
Uv Photodetector ◽  
Organic Photodetector ◽  
Visible Blind

The visible-blind ultraviolet (UV) photodetector can detect UV signals and is not interfered by visible light or infrared light in the environment. In order to realize high-performance visible-blind UV organic...

scholarly journals Organic Light-Emitting Transistors with Simultaneous Enhancement of Optical Power and External Quantum Efficiency via Conjugated Polar Polymer Interlayers

2018 ◽  
Vol 10 (30) ◽  
pp. 25580-25588 ◽  
Author(s):  
Mario Prosa ◽  
Emilia Benvenuti ◽  
Mariacecilia Pasini ◽  
Umberto Giovanella ◽  
Margherita Bolognesi ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency ◽  
Optical Power ◽  
Light Emitting ◽  
Organic Light ◽  
Light Emitting Transistors ◽  
Polar Polymer

Microcrystalline (Si,Ge):H Solar Cells

2003 ◽  
Vol 762 ◽  
Author(s):  
Jianhua Zhu ◽  
Vikram L. Dalal
Keyword(s):  
Solar Cells ◽  
Buffer Layer ◽  
Quantum Efficiency ◽  
Fill Factor ◽  
Open Circuit Voltage ◽  
Defect Density ◽  
Cell Structure ◽  
Open Circuit ◽  
Base Layer ◽  
Ecr Plasma

AbstractWe report on the growth and properties of microcrystalline Si:H and (Si,Ge):H solar cells on stainless steel substrates. The solar cells were grown using a remote, low pressure ECR plasma system. In order to crystallize (Si,Ge), much higher hydrogen dilution (∼40:1) had to be used compared to the case for mc-Si:H, where a dilution of 10:1 was adequate for crystallization. The solar cell structure was of the p+nn+ type, with light entering the p+ layer. It was found that it was advantageous to use a thin a-Si:H buffer layer at the back of the cells in order to reduce shunt density and improve the performance of the cells. A graded gap buffer layer was used at the p+n interface so as to improve the open-circuit voltage and fill factor. The open circuit voltage and fill factor decreased as the Ge content increased. Quantum efficiency measurements indicated that the device was indeed microcrystalline and followed the absorption characteristics of crystalline ( Si,Ge). As the Ge content increased, quantum efficiency in the infrared increased. X-ray measurements of films indicated grain sizes of ∼ 10nm. EDAX measurements were used to measure the Ge content in the films and devices. Capacitance measurements at low frequencies ( ~100 Hz and 1 kHz) indicated that the base layer was indeed behaving as a crystalline material, with classical C(V) curves. The defect density varied between 1x1016 to 2x1017/cm3, with higher defects indicated as the Ge concentration increased.

Demonstration of ultra-small (0.2%) for mini-displays

2020 ◽  
Vol 14 (1) ◽  
pp. 011004
Author(s):  
Shubhra S. Pasayat ◽  
Chirag Gupta ◽  
Matthew S. Wong ◽  
Ryan Ley ◽  
Michael J. Gordon ◽  
...  
Keyword(s):  
Quantum Efficiency ◽  
External Quantum Efficiency
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