학술논문
Exploitation of Improved Long‐Term Stability and Enhanced Photoconversion Efficiency of Organic Photovoltaics Using Flexible Transparent Conducting Electrode with Dual Functions of Antireflection and Ultrahigh Moisture Barrier
Document Type
Academic Journal
Source
Advanced Energy and Sustainability Research. December 2021, Vol. 2 Issue 12
Subject
Language
English
Abstract
Introduction Organic photovoltaics (OPVs) have been extensively investigated as renewable energy generation sources that combine the advantages of flexibility, lightweight, low cost, semitransparency, and use of a roll‐to‐roll process.[sup.[] [sup.1–4] [...]
A structure of flexible glass/flexible transparent conducting electrode (TCE) comparable with the conventional glass/indium tin oxide (ITO) substrate is proposed by combining an Ag NW + PEDOT:PSS hybrid TCE (h‐TCE) with triple‐layer a‐SiN[sub.x]:H/n‐SiO[sub.x]N[sub.y]/h‐SiO[sub.x] ultrahigh barrier (UHB) films. The UHB films have dual functions of both moisture barriers with a water vapor transmission rate (WVTR) of 1.6 × 10[sup.−5] × g m[sup.−2] day[sup.−1] and antireflection (AR) with a gradient refractive index. Flexible PTB7:PC[sub.70]BM‐based organic photovoltaics (OPVs) with the AR‐UHB film achieve a maximum power conversion efficiency (PCE) of η[sub.max] = 8.33%, saturation current density (J[sub.sc]) of 17.67 mA cm[sup.−2], and external quantum efficiency (EQE) of 63.3%, which are higher than η[sub.max] = 7.63%, J[sub.sc] = 15.25 mA cm[sup.−2], and EQE = 59.26% of the OPVs on glass/ITO. These result from the increase in the absorption of the donor PTB7 due to the AR effect of the UHB films. A long‐term stability of the AR‐UHB encapsulation layer in damp heat (40 °C/85% relative humidity [RH]) is confirmed by the result that the measured T[sub.80] and T[sub.50] values for the OPV device on glass/ITO encapsulated with the AR‐UHB film are about 1008 h (42 days) and 2205 h (92 days), respectively.
A structure of flexible glass/flexible transparent conducting electrode (TCE) comparable with the conventional glass/indium tin oxide (ITO) substrate is proposed by combining an Ag NW + PEDOT:PSS hybrid TCE (h‐TCE) with triple‐layer a‐SiN[sub.x]:H/n‐SiO[sub.x]N[sub.y]/h‐SiO[sub.x] ultrahigh barrier (UHB) films. The UHB films have dual functions of both moisture barriers with a water vapor transmission rate (WVTR) of 1.6 × 10[sup.−5] × g m[sup.−2] day[sup.−1] and antireflection (AR) with a gradient refractive index. Flexible PTB7:PC[sub.70]BM‐based organic photovoltaics (OPVs) with the AR‐UHB film achieve a maximum power conversion efficiency (PCE) of η[sub.max] = 8.33%, saturation current density (J[sub.sc]) of 17.67 mA cm[sup.−2], and external quantum efficiency (EQE) of 63.3%, which are higher than η[sub.max] = 7.63%, J[sub.sc] = 15.25 mA cm[sup.−2], and EQE = 59.26% of the OPVs on glass/ITO. These result from the increase in the absorption of the donor PTB7 due to the AR effect of the UHB films. A long‐term stability of the AR‐UHB encapsulation layer in damp heat (40 °C/85% relative humidity [RH]) is confirmed by the result that the measured T[sub.80] and T[sub.50] values for the OPV device on glass/ITO encapsulated with the AR‐UHB film are about 1008 h (42 days) and 2205 h (92 days), respectively.