skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Efficient light trapping and interface engineering for performance enhancement in PTB7-Th: PC 70 BM organic solar cells

Authors:
; ; ; ; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1396386
Grant/Contract Number:
AC36-08GO28308
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Organic Electronics
Additional Journal Information:
Journal Volume: 41; Journal Issue: C; Related Information: CHORUS Timestamp: 2017-10-04 16:35:21; Journal ID: ISSN 1566-1199
Publisher:
Elsevier
Country of Publication:
Netherlands
Language:
English

Citation Formats

Borse, Kunal, Sharma, Ramakant, Sagar, H. P., Reddy, P. Anil, Gupta, Dipti, and Yella, Aswani. Efficient light trapping and interface engineering for performance enhancement in PTB7-Th: PC 70 BM organic solar cells. Netherlands: N. p., 2017. Web. doi:10.1016/j.orgel.2016.11.016.
Borse, Kunal, Sharma, Ramakant, Sagar, H. P., Reddy, P. Anil, Gupta, Dipti, & Yella, Aswani. Efficient light trapping and interface engineering for performance enhancement in PTB7-Th: PC 70 BM organic solar cells. Netherlands. doi:10.1016/j.orgel.2016.11.016.
Borse, Kunal, Sharma, Ramakant, Sagar, H. P., Reddy, P. Anil, Gupta, Dipti, and Yella, Aswani. Wed . "Efficient light trapping and interface engineering for performance enhancement in PTB7-Th: PC 70 BM organic solar cells". Netherlands. doi:10.1016/j.orgel.2016.11.016.
@article{osti_1396386,
title = {Efficient light trapping and interface engineering for performance enhancement in PTB7-Th: PC 70 BM organic solar cells},
author = {Borse, Kunal and Sharma, Ramakant and Sagar, H. P. and Reddy, P. Anil and Gupta, Dipti and Yella, Aswani},
abstractNote = {},
doi = {10.1016/j.orgel.2016.11.016},
journal = {Organic Electronics},
number = C,
volume = 41,
place = {Netherlands},
year = {Wed Feb 01 00:00:00 EST 2017},
month = {Wed Feb 01 00:00:00 EST 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.orgel.2016.11.016

Citation Metrics:
Cited by: 4works
Citation information provided by
Web of Science

Save / Share:
  • Advances in materials design and device engineering led to inverted organic solar cells (i-OSCs) with superior power conversion efficiencies (PCEs) to their conventional counterparts, in addition to the well-known better ambient stability. Despite the significant progress, however, it has so far been unclear how the morphologies of the photoactive layer and its interface with the cathode modifying layer impact device performance. Here, we report an in-depth morphology study of the i-OSC active and cathode modifying layers, employing a model system with the well-established bulk-heterojunction, PTB7:PC 71BM as the active layer and poly-[(9,9-bis(3 -( N,N-dimethylamino)propyl)-2,7-fluorene)- alt-2,7-(9,9-dioctylfluorene)] (PFN) as the cathode surfacemore » modifying layer. We have also identified the role of a processing additive, 1,8-diiodooctane (DIO), used in the spin-casting of the active layer to increase PCE. Using a variety of characterization techniques, we demonstrate that the high PCEs of i-OSCs are due to the smearing (diffusion) of electron-accepting PC 71BM into the PFN layer, resulting in improved electron transport. The PC 71BM diffusion occurs after spin-casting the active layer onto the PFN layer, when residual solvent molecules act as a plasticizer. Furthermore, the DIO additive, with a higher boiling point than the host solvent, has a longer residence time in the spin-cast active layer, resulting in more PC 71BM smearing and therefore more efficient electron transport. This work provides important insight and guidance to further enhancement of i-OSC performance by materials and interface engineering.« less
  • Advances in material design and device engineering led to inverted organic solar cells (i-OSCs) with superior power conversion efficiencies (PCEs) compared to their “conventional” counterparts, in addition to the well-known better ambient stability. Here, we report an in-depth morphology study of the i-OSC active and cathode modifying layers, employing a model system with a wellestablished bulk-heterojunction, PTB7:PC71BM as the active layer and poly-[(9,9-bis(3’-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN) as the cathode surface modifyinglayer. We have also identified the role of a processing additive, 1,8-diiodooctane (DIO), used in the spin-casting of the active layer to increase PCE. Using various characterization techniques, we demonstrate that themore » high PCEs of i-OSCs are due to the diffusion of electron-accepting PC71BM into the PFN layer, resulting in improved electron transport. The diffusion occurs when residual solvent molecules in the spun-cast film act as a plasticizer. Addition of DIO to the casting solution results in more PC71BM diffusion and therefore more efficient electron transport. This work provides important insight and guidance to further enhancement of i-OSC performance by materials and interface engineering.« less
  • We have investigated the effects induced by periodic nanosphere arrays on the performance of organic solar cells (OSCs). Two-dimensional periodic arrays of polystyrene nanospheres were formed by using a colloidal lithography method together with plasma etching to trim down the size to various degrees on the substrates of OSCs. It is found that the devices prepared on such substrates can have improved light harvesting, resulting in as high as 35% enhancement in power conversion efficiency over that of the reference devices. The measured external quantum efficiency and finite-difference time-domain simulation reveal that the controlled periodic morphology of the substrate canmore » efficiently increase light scattering in the device and thus enhance the absorption of incident light.« less
  • An efficient light trapping scheme named as textured conductive photonic crystal (TCPC) has been proposed and then applied as a back-reflector (BR) in n-i-p hydrogenated amorphous silicon (a-Si:H) solar cell. This TCPC BR combined a flat one-dimensional photonic crystal and a randomly textured surface of chemically etched ZnO:Al. Total efficiency enhancement was obtained thanks to the sufficient conductivity, high reflectivity and strong light scattering of the TCPC BR. Unwanted intrinsic losses of surface plasmon modes are avoided. An initial efficiency of 9.66% for a-Si:H solar cell was obtained with short-circuit current density of 14.74 mA/cm{sup 2}, fill factor of 70.3%, andmore » open-circuit voltage of 0.932 V.« less