Reconciling the value of Schottky barriers in small molecular organic photovoltaics from J-V and C-V measurements at low temperatures towards the estimation of open circuit voltage at 0 K
Journal
Organic Electronics: physics, materials, applications
Journal Volume
73
Pages
166-171
Date Issued
2019
Author(s)
Biring, S.
Sung, Y.-M.
Nguyen, T.P.
Li, Y.-Z.
Lee, C.-C.
Yi Chan, A.H.
Pal, B.
Sen, S.
Liu, S.-W.
Abstract
Open circuit voltage of a photovoltaic system, in general, is constrained by the Schottky barrier (SB) heights formed at the electrodes. Here, the SB heights which are inhomogeneous in nature at the anode-semiconductor junction of a donor-acceptor-acceptor molecule, 2-[(7-(4-[N,N-bis(4-methylphenyl)amino]phenyl)-2,1,3-benzothia-diazol-4-yl)methylene] propane-dinitrile (DTDCPB), mixed with C70 as a bulk heterojunction have been studied thoroughly by inserting an insulating layer of MoO3 with different thicknesses (6 nm, 12 nm, 18 nm) and measuring the current density-voltage (J-V) and capacitance-voltage (C–V) characteristics of the photovoltaics under a large temperature range of 100K–300 K for proper estimation of open circuit voltage (Voc). Experimental results reveal a linear inverse temperature dependence of SB heights in the whole temperature range. The mismatch in the extracted values of SB heights from the independent measurements of J-V and C–V vanishes under the consideration of non-linear temperature dependence of built-in potential (Vbi) leading to the legitimate prediction of Voc. © 2019 Elsevier B.V.
Subjects
CV; DTDCPB:C70; Inhomogeneous Schottky barriers; J-V; Low temperature; Open circuit voltage
SDGs
Other Subjects
Capacitance; Electrodes; Heterojunctions; Molybdenum oxide; Photovoltaic cells; Schottky barrier diodes; Temperature distribution; Timing circuits; Bulk heterojunction; DTDCPB:C70; Independent measurement; Inverse temperatures; Low temperatures; Organic photovoltaics; Photovoltaic systems; Schottky barriers; Open circuit voltage
Type
journal article