Vertical-Phase-Locking Effect in Efficient and Stable All-Polymer-Hosted Solar Cells

Abstract

All-polymer solar cells with bulk-heterojunction films composed of polymeric donors and acceptors are distinguished for their outstanding device stability. However, unfavorable thermodynamic mixing of polymers induced severe phase-separated morphology related to electron−phonon coupling, limiting the practical development of high-efficiency organic solar cells (OSCs). Herein, we obtain an enhanced power conversion efficiency in all-polymer-hosted OSCs prepared by a guest−nanofill strategy, where a third component (small molecule guest, B1) is employed to manipulate the electron−phonon interactions associated with the diffusion-mediated excitons dissociation and charge transport properties of the binary film. Encouragingly, the guest-nanofilled OSCs exhibit notably enhanced thermal stability, as the nanofiller B1 molecules allow the vertical distribution of the donor: acceptor to exhibit a locked pattern during the aging process, which can be figuratively termed as "vertical-phase-locking effect". The guest−nanofill strategy in this work provides a unique approach toward the development of high-performance allpolymer electronics.

Restrained energetic disorder for high-efficiency organic solar cells via a solid additive

“…where E(0) is the band gap energy at 0 K, y is the average phonon temperature, and a is the intensity of electron-lattice interaction. 40,[42][43][44] Fig. 5e delivers the fittings based on eqn (1) and shows that the TMB-treated film has weak electron-lattice interaction with an intensity of 51 meV while that of the DIO-treated film is 112 meV, which further verifies the enhanced delocalization property in TMB-processed films.…”

Enhancing Photon Utilization Efficiency for High‐Performance Organic Photovoltaic Cells via Regulating Phase‐Transition Kinetics

“…[ 65 ] $$\[{N_{\rm{t}}}\left( E \right) = \frac{{{N_{\rm{t}}}}}{{\sqrt {2\pi } \delta }}\exp \left[ { - \frac{{{{\left( {{E_{\rm{t}}} - E} \right)}^2}}}{{2{\delta ^2}}}} \right]\]$$where N t and E t represent the trap‐state density and the center of the density of states (DOS), respectively, and δ is the energy disorder. [ 9,66 ] The 2D images and corresponding 1D curves of the capacitance–voltage (C–V) data measured in dark and under illumination conditions are illustrated in Figures S21 and S22, Supporting Information. The fitted curves related to the trap density and DOS are shown in Figure 5b,c, respectively.…”

“…where N t and E t represent the trap-state density and the center of the density of states (DOS), respectively, and δ is the energy disorder. [9,66] The 2D images and corresponding 1D curves of the capacitance-voltage (C-V) data measured in dark and under illumination conditions are illustrated in Figures S21 and S22 5c). This is because PBDB-TF slightly reduced the crystallinity of the PBQx-TCl:eC9-2Cl-based system and increased the crystallinity of the PBDB-TF:eC9-2Cl-based system.…”

Dredging photocarrier trapping pathways via “charge bridge” driven exciton–phonon decoupling enables efficient and photothermal stable quaternary organic solar cells

“…These PL spectra feature a gradually shifted peak position towards higher energy and spectral line broadening, with an increase in temperature. The exciton-phonon coupling interactions can be deduced from the temperature-dependent PL linewidths, which is quantitatively described by the following equation, 43,44 GðTÞ…”

“…These PL spectra feature a gradually shifted peak position towards higher energy and spectral line broadening, with an increase in temperature. The exciton–phonon coupling interactions can be deduced from the temperature-dependent PL linewidths, which is quantitatively described by the following equation, 43,44 where Γ i is expressed as the inhomogeneous linewidth of the blends, a is regarded as the density of the non-radiative recombination center, E a is considered to be the energy barrier of back charge recombination from electronic to excitonic excitations for Y-series NFAs, 45 b is defined as the coefficient of exciton–phonon coupling. The detailed fitting results are presented in Fig.…”