scholarly journals Designing an Ultrathin Film Spectrometer Based on III-Nitride Light-Absorbing Nanostructures

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 760
Author(s):  
Juhyeon Kim ◽  
Srinivasa Cheekati ◽  
Tuba Sarwar ◽  
Pei-Cheng Ku
Keyword(s):  
Quantum Wells ◽  
Light Harvesting ◽  
Local Strain ◽  
Strain Engineering ◽  
Multiple Quantum ◽  
Group Iii ◽  
Harvesting Efficiency ◽  
Light Harvesting Efficiency ◽  
Back Reflector ◽  
Visible Wavelengths

In this paper, a spectrometer design enabling an ultrathin form factor is proposed. Local strain engineering in group III-nitride semiconductor nanostructured light-absorbing elements enables the integration of a large number of photodetectors on the chip exhibiting different absorption cut-off wavelengths. The introduction of a simple cone-shaped back-reflector at the bottom side of the substrate enables a high light-harvesting efficiency design, which also improves the accuracy of spectral reconstruction. The cone-shaped back-reflector can be readily fabricated using mature patterned sapphire substrate processes. Our design was validated via numerical simulations with experimentally measured photodetector responsivities as the input. A light-harvesting efficiency as high as 60% was achieved with five InGaN/GaN multiple quantum wells for the visible wavelengths.

scholarly journals SWCNT photocathodes sensitised with InP/ZnS core–shell nanocrystals

2016 ◽  
Vol 4 (16) ◽  
pp. 3379-3384 ◽  
Author(s):  
Thomas J. Macdonald ◽  
Daniel D. Tune ◽  
Melissa R. Dewi ◽  
Joseph C. Bear ◽  
Paul D. McNaughter ◽  
...  
Keyword(s):  
Light Harvesting ◽  
Core Shell ◽  
The Future ◽  
Harvesting Efficiency ◽  
Light Harvesting Efficiency

Increasing the light harvesting efficiency of photocathodes is an integral part of optimising the future efficiencies of solar technologies.

Enhancing the quasi-theoretical photocurrent density of ZnO nanorods via a lukewarm hydrothermal method

Nanoscale ◽  
2020 ◽  
Vol 12 (23) ◽  
pp. 12292-12299
Author(s):  
Ying-Chu Chen ◽  
Zhi-Jie Wu ◽  
Yu-Kuei Hsu
Keyword(s):  
Hydrothermal Method ◽  
Water Splitting ◽  
Light Harvesting ◽  
Zno Nanorods ◽  
Photocurrent Density ◽  
Photoelectrochemical Water Splitting ◽  
Harvesting Efficiency ◽  
Light Harvesting Efficiency

Anti-reflection enhanced the light harvesting efficiency of a ∼10-μm-long 1D ZnO NRA, which is evidently manifested in the quasi-theoretical photocurrent density that reached ∼0.9 mA cm−2 for solar photoelectrochemical water splitting.

Performance of TiO2 Aggregates-Based Dye Solar Cells

2013 ◽  
Vol 737 ◽  
pp. 137-144 ◽  
Author(s):  
Norani Muti Mohamed ◽  
Siti Nur Azella Zaine
Keyword(s):  
Solar Cells ◽  
Light Scattering ◽  
Water Content ◽  
Calcination Temperature ◽  
Conversion Efficiency ◽  
Light Harvesting ◽  
Dye Solar Cells ◽  
Harvesting Efficiency ◽  
Light Harvesting Efficiency ◽  
20 Nm

TiO2 aggregates-based dye solar cells (DSCs) have gained an increasing interest due to their better light harvesting efficiency as a result of enhanced light scattering effect from the submicron spherical aggregates that can generate more electrons and the high internal surface area for dye chemisorption provided by nanocrystallites which made up the aggregates. Optimized TiO2 aggregates (0.45 µm) composing of nanocrystallites (10-40 nm) with desired physicochemical properties for enhanced overall light conversion efficiency of DSC were synthesized by varying the calcination temperature and water content in the hydrolysis of titanium alkoxide in ethanol. TiO2 aggregates obtained were characterized using FESEM, XRD and UV-Vis spectroscopy. The assembled DSCs were then evaluated using solar simulator under AM 1.5 (100 mW/cm2) simulated sunlight. Nanocrystallites were found to have an increasing size of 12 nm to 36 nm with increasing calcination temperature of 400C to 600C. Sample of aggregates calcined at 500C recorded the highest efficiency (4.456%) as the 20-nm nanocrystallites produced is considered to be the optimum size for dye absorption. With higher water content in the hydrolysis process, the aggregates lose their spherical shapes resulting in lower absorption intensity indicating the occurrence of low light scattering in the TiO2 film. Highest conversion efficiency was observed for DSC that used well-defined spherical TiO2 aggregates composing of 20-nm nanocrystallites which were synthesized using ethanol with low water content (0.9 vol%) followed by calcination at 500C. Thus, optimized TiO2 nanocrystallites which form spherical aggregate is critical in order to improve light harvesting efficiency of DSCs.

Bismuth silicate photocatalysts with enhanced light harvesting efficiency by photonic crystal

2019 ◽  
Vol 810 ◽  
pp. 151839 ◽  
Author(s):  
Yuanting Wu ◽  
Jian Lu ◽  
Menglong Li ◽  
Jun Yuan ◽  
Penghong Wu ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Light Harvesting ◽  
Bismuth Silicate ◽  
Harvesting Efficiency ◽  
Light Harvesting Efficiency
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