Reconciling models of interfacial state kinetics and device performance in organic solar cells: impact of the energy offsets on the power conversion efficiency

Abstract

We present a new framework to study organic photovoltaic devices in which a model that integrates device physics with excited state dynamics is applied to explain transient and steady-state spectroscopic and optoelectronic measurements.

Fibrillization of Non‐Fullerene Acceptors Enables 19% Efficiency Pseudo‐Bulk Heterojunction Organic Solar Cells

“…Organic solar cells (OSCs) have shown great potential as a clean energy technology due to their merits including mechanical flexibility, lightweight, and solution-processibility. [1][2][3] With extensive efforts from researchers on molecular design and device engineering, [4][5][6][7] the performance of OSCs has been greatly improved in the last few years, leading to a power conversion efficiency (PCE) surpassing 19% in single-junction OSCs. [8][9][10] In general, the architecture of OSC is featured with In this work, we present an approach to form a refined fibril structure of a recently reported high-performance NFA L8-BO [31] with the assistance of a fused-ring solvent additive 1-fluoronaphthalene (FN) to substantially improve device PCE.…”

“…Organic solar cells (OSCs) have shown great potential as a clean energy technology due to their merits including mechanical flexibility, lightweight, and solution‐processibility. [ 1–3 ] With extensive efforts from researchers on molecular design and device engineering, [ 4–7 ] the performance of OSCs has been greatly improved in the last few years, leading to a power conversion efficiency (PCE) surpassing 19% in single‐junction OSCs. [ 8–10 ] In general, the architecture of OSC is featured with electrodes and interfacial buffer layers sandwiching a bulk heterojunction (BHJ) active layer, where the BHJ active layer composes intermixed networks of electron donating and accepting materials.…”

Voltage-dependent excitation dynamics in UV-absorbing organic photovoltaics with efficient charge transfer exciton emission

“…The driving force (DE) for charge transfer is defined as the difference between the energy of the donor singlet (S 1 ) and the CTE state of its HJ. 13,35,36 This value is approximated experimentally as the difference between the optical gap (E G,opt ) and CTE energy and is given in Table 1.…”

Fast Recombination of Charge-Transfer State in Organic Photovoltaic Composite of P3HT and Semiconducting Carbon Nanotubes Is the Reason for Its Poor Photovoltaic Performance

“…The optical absorption and luminescence of CTS are often weak and masked by the corresponding signals from the other species (singlet and triple excitons, free charges) in the donor/acceptor composite. In favorable cases, some information about spectral and kinetic parameters of CTS can be obtained by the optical methods [ 11 , 12 , 13 ]. However, these methods are generally unable to provide information about the structure of CTS.…”