z-logo
Premium
The Impact of Grain Alignment of the Electron Transporting Layer on the Performance of Inverted Bulk Heterojunction Solar Cells
Author(s) -
Murali Banavoth,
Labban Abdulrahman El,
Eid Jessica,
Alarousu Erkki,
Shi Dong,
Zhang Qiang,
Zhang Xixiang,
Bakr Osman M.,
Mohammed Omar F.
Publication year - 2015
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201500924
Subject(s) - materials science , sputter deposition , conductivity , energy conversion efficiency , optoelectronics , short circuit , grain size , polymer solar cell , analytical chemistry (journal) , sputtering , thin film , nanotechnology , composite material , voltage , chemistry , organic chemistry , physics , quantum mechanics
This report presents a new strategy for improving solar cell power conversion efficiencies (PCEs) through grain alignment and morphology control of the ZnO electron transport layer (ETL) prepared by radio frequency (RF) magnetron sputtering. The systematic control over the ETL's grain alignment and thickness is shown, by varying the deposition pressure and operating substrate temperature during the deposition. Notably, a high PCE of 6.9%, short circuit current density ( J sc ) of 12.8 mA cm −2 , open circuit voltage ( V oc ) of 910 mV, and fill factor of 59% are demonstrated using the poly(benzo[1,2‐ b :4,5‐ b ′]dithiophene–thieno[3,4‐ c ]pyrrole‐4,6‐dione):[6,6]‐phenyl‐C 71 ‐butyric acid methyl ester polymer blend with ETLs prepared at room temperature exhibiting oriented and aligned rod‐like ZnO grains. Increasing the deposition temperature during the ZnO sputtering induces morphological cleavage of the rod‐like ZnO grains and therefore reduced conductivity from 7.2 × 10 −13 to ≈1.7 × 10 −14 S m −1 and PCE from 6.9% to 4.28%. An investigation of the charge carrier dynamics by femtosecond (fs) transient absorption spectroscopy with broadband capability reveals clear evidence of faster carrier recombination for a ZnO layer deposited at higher temperature, which is consistent with the conductivity and device performance.

This content is not available in your region!

Continue researching here.

Having issues? You can contact us here