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Title: Light management in perovskite solar cells and organic LEDs with microlens arrays

Abstract

Here, we demonstrate enhanced absorption in solar cells and enhanced light emission in OLEDs by light interaction with a periodically structured microlens array. We simulate n-i-p perovskite solar cells with a microlens at the air-glass interface, with rigorous scattering matrix simulations. The microlens focuses light in nanoscale regions within the absorber layer enhancing the solar cell. Optimal period of ~700 nm and microlens height of ~800-1000 nm, provides absorption (photocurrent) enhancement of 6% (6.3%). An external polymer microlens array on the air-glass side of the OLED generates experimental and theoretical enhancements >100%, by outcoupling trapped modes in the glass substrate.

Authors:
ORCiD logo [1];  [1];  [2];  [3];  [1]
  1. Ames Lab. and Iowa State Univ., Ames, IA (United States)
  2. Ames Lab., Ames, IA (United States)
  3. Iowa State Univ., Ames, IA (United States)
Publication Date:
Research Org.:
Ames Laboratory (AMES), Ames, IA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1362277
Report Number(s):
IS-J-9332
Journal ID: ISSN 1094-4087; OPEXFF
Grant/Contract Number:
AC02-05CH11231; AC02-07CH11385
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Optics Express
Additional Journal Information:
Journal Volume: 25; Journal Issue: 9; Journal ID: ISSN 1094-4087
Publisher:
Optical Society of America (OSA)
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; nanomaterials; polymers; optoelectronics; solar energy

Citation Formats

Peer, Akshit, Biswas, Rana, Park, Joong -Mok, Shinar, Ruth, and Shinar, Joseph. Light management in perovskite solar cells and organic LEDs with microlens arrays. United States: N. p., 2017. Web. doi:10.1364/OE.25.010704.
Peer, Akshit, Biswas, Rana, Park, Joong -Mok, Shinar, Ruth, & Shinar, Joseph. Light management in perovskite solar cells and organic LEDs with microlens arrays. United States. doi:10.1364/OE.25.010704.
Peer, Akshit, Biswas, Rana, Park, Joong -Mok, Shinar, Ruth, and Shinar, Joseph. Fri . "Light management in perovskite solar cells and organic LEDs with microlens arrays". United States. doi:10.1364/OE.25.010704. https://www.osti.gov/servlets/purl/1362277.
@article{osti_1362277,
title = {Light management in perovskite solar cells and organic LEDs with microlens arrays},
author = {Peer, Akshit and Biswas, Rana and Park, Joong -Mok and Shinar, Ruth and Shinar, Joseph},
abstractNote = {Here, we demonstrate enhanced absorption in solar cells and enhanced light emission in OLEDs by light interaction with a periodically structured microlens array. We simulate n-i-p perovskite solar cells with a microlens at the air-glass interface, with rigorous scattering matrix simulations. The microlens focuses light in nanoscale regions within the absorber layer enhancing the solar cell. Optimal period of ~700 nm and microlens height of ~800-1000 nm, provides absorption (photocurrent) enhancement of 6% (6.3%). An external polymer microlens array on the air-glass side of the OLED generates experimental and theoretical enhancements >100%, by outcoupling trapped modes in the glass substrate.},
doi = {10.1364/OE.25.010704},
journal = {Optics Express},
number = 9,
volume = 25,
place = {United States},
year = {Fri Apr 28 00:00:00 EDT 2017},
month = {Fri Apr 28 00:00:00 EDT 2017}
}

Journal Article:
Free Publicly Available Full Text
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Citation Metrics:
Cited by: 3works
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  • Over the last decade, polymer solar cells (PSCs) have attracted a lot of attention and highest power conversion efficiencies (PCE) are now close to 10%. Here we employ an optical structure – the microlens array (MLA) – to increase light absorption inside the active layer, and PCE of PSCs increased even for optimized devices. Normal incident light rays are refracted at the MLA and travel longer optical paths inside the active layers. Two PSC systems – poly(3-hexylthiophene-2,5-diyl):(6,6)-phenyl C61 butyric acid methyl ester (P3HT:PCBM) and poly[[9-(1-octylnonyl)-9H-carbazole-2,7-diyl]-2,5-thiophenediyl-2,1,3-benzothiadiazole-4,7-diyl-2,5-thiophenediyl]:(6,6)-phenyl C71 butyric acid methyl ester (PCDTBT:PC70BM) – were investigated. In the P3HT:PCBM system, MLA increasedmore » the absorption, absolute external quantum efficiency, and the PCE of an optimized device by [similar]4.3%. In the PCDTBT:PC70BM system, MLA increased the absorption, absolute external quantum efficiency, and PCE by more than 10%. In addition, simulations incorporating optical parameters of all structural layers were performed and they support the enhancement of absorption in the active layer with the assistance of MLA. Our results show that utilizing MLA is an effective strategy to further increase light absorption in PSCs, in which optical losses account for [similar]40% of total losses. MLA also does not pose materials processing challenges to the active layers since it is on the other side of the transparent substrate.« less
  • Cited by 6
  • The TiO{sub 2} nanorod arrays with the length of 70 nm, the diameter of 20 nm, and the areal density of 1000 µm{sup −2} were firstly prepared by the hydrothermal method using the aqueous grown solution of 38 mM titanium isopropoxide and 6 M hydrochloric acid at 170 °C for 60 min. Over-500 nm-thickness CH{sub 3}NH{sub 3}PbI{sub 3−x}Br{sub x} absorber layers were successfully obtained by sequential deposition routes using 1.7 M PbI{sub 2}·DMSO complex precursor solution and 0.465 M isopropanol solution of the methylammonium halide mixture with the molar ratio of CH{sub 3}NH{sub 3}I/CH{sub 3}NH{sub 3}Br=85/15. The perovskite solar cellsmore » based on the TiO{sub 2} nanorod array and 560 nm-thickness CH{sub 3}NH{sub 3}PbI{sub 3−x}Br{sub x} absorber layer exhibited the best photoelectric conversion efficiency (PCE) of 15.93%, while the corresponding planar perovskite solar cells without the TiO{sub 2} nanorod array and with 530 nm-thickness CH{sub 3}NH{sub 3}PbI{sub 3−x}Br{sub x} absorber layer gave the best PCE of 12.82% at the relative humidity of 50–54%. - Graphical abstract: The TiO{sub 2} nanorod arrays with the length of 70 nm, the diameter of 20 nm, and the areal density of 1000 µm{sup −2} were prepared by the hydrothermal method using the aqueous grown solution of 38 mM titanium isopropoxide and 6 M hydrochloric acid at 170 °C for 60 min. The optimal annealing temperature of TiO{sub 2} nanorod arrays was 450 °C. The perovskite solar cells based on the TiO{sub 2} nanorod array and 560 nm-thickness CH{sub 3}NH{sub 3}PbI{sub 3−x}Br{sub x} absorber layer exhibited the best photoelectric conversion efficiency (PCE) of 15.93% and the average PCE of 13.41±2.52%, while the corresponding planar perovskite solar cells without the TiO{sub 2} nanorod array and with 530 nm-thickness CH{sub 3}NH{sub 3}PbI{sub 3−x}Br{sub x} absorber layer gave the best PCE of 12.82% and the average PCE of 10.54±2.28% at the relative humidity of 50–54%. - Highlights: • Preparation of TiO{sub 2} nanorod array with length of 70 nm and density of 1000 µm{sup −2}. • Influence of annealing temperatures on the -OH content of TiO{sub 2} nanorod arrays. • Preparation of over-500 nm-thickness CH{sub 3}NH{sub 3}PbI{sub 3−x}Br{sub x} absorber layer. • Combination of short-length TiO{sub 2} nanorod array and high-thickness perovskite layer. • The best and average PCE with TiO{sub 2} array of 15.93% and 13.41±2.52% at 50–54% RH.« less
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  • We report a simple method to mitigate ultra-violet (UV) degradation in TiO{sub 2} based perovskite solar cells (PSC) using a transparent luminescent down-shifting (DS) YVO{sub 4}:Eu{sup 3+} nano-phosphor layer. The PSC coated with DS phosphor showed an improvement in stability under prolonged illumination retaining more than 50% of its initial efficiency, whereas PSC without the phosphor layer degraded to ∼35% of its initial value. The phosphor layer also provided ∼8.5% enhancement in photocurrent due to DS of incident UV photons into additional red photons. YVO{sub 4}:Eu{sup 3+} layer thus served a bi-functional role in PSC by reducing photo-degradation as wellmore » as enhancing energy conversion efficiency.« less