Device and morphological engineering of organic solar cells for enhanced charge transport and photovoltaic performance

Abstract

Abstract. Conjugated polymers are potential materials for photovoltaic applications due to their high absorption coefficient, mechanical flexibility, and solution-based processing for low-cost solar cells. A bulk heterojunction (BHJ) structure made of donor-acceptor composite can lead to high charge transfer and power conversion efficiency. Active layer morphology is a key factor for device performance. Film formation processes (e.g., spray-coating, spin-coating, and dip-coating), post-treatment (e.g., annealing and UV ozone treatment), and use of additives are typically used to engineer the morphology, which optimizes physical properties, such as molecular configuration, miscibility, lateral and vertical phase separation. We will review electronic donoracceptor interactions in conjugated polymer composites, the effect of processing parameters and morphology on solar cell performance, and charge carrier transport in polymer solar cells. This review provides the basis for selection of different processing conditions for optimized nanomorphology of active layers and reduced bimolecular recombination to enhance open-circuit voltage, short-circuit current density, and fill factor of BHJ solar cells.

Illumination alters the structure of gels formed from the model optoelectronic material P3HT

“…Designing these polymer active layers to best facilitate charge carrier creation, movement, and collection has been a focal point of research in the area for decades. 1,2,3,4,5 However much room for improvement remains as device efficiency and stability weaknesses persist. 6 To best optimize crucial active layer performance parameters such as exciton dissociation efficiencies, the donor and acceptor layers must be engineered in such a way that interfacial area is maximized to ensure effective charge transport pathways within range of typical exciton dissociation lengths in these materials (~10nm).…”

Extensive investigation of structural, electronic, optical, and thermoelectric properties of hybrid perovskite ( CH 3 NH 3 PbBr 3 ) with mechanical stability constants

“…Figure 3A shows the electronic band structure with the total density of state of CH 3 NH 3 PbBr 3 and Figure 3B represents the PDOS of different orbital component of Pb, Br and CH 3 NH 3 . As we have discussed in previous article for CH 3 To study the electronic structure and band gap, several ex-correlation potentials such as Becke-Johnson (BJ), 31 WC-GGA, 32 Tran-Blaha modified Becke-Johnson (TB-mBJ), 38 PBE-GGA, 45 and LDA 46 have been used without the incorporation of spin orbit coupling. The nature of band gap is direct and exists at R (0.5, 0.5, 0.5) point in the Brillouin zone.…”

“…The speed-up world population expansion and postindustrialized period bring into consideration any unexpected requirement of energy, answerable for environment dilemma sustainable growth concerns with financial challenges. [1][2][3] Wind, sun, hydraulic, biomass, and geothermal have been studied and to take benefit of the renewable energy sources, we have to develop the latest technologies. Sunbeam has huge potential as an energy resource among irradiance 1.8 × 10 14 kW at the earth's outside, which can convert into electrical energy with a negligible natural impact.…”

“…Figure 6C,G represents the variation of thermal F I G U R E 6 Calculated thermoelectric coefficients for CH3 NH 3 PbBr 3 as a function of n-type (A-D) and p-type (E-H) doping concentration at temperature range from 300 K to 800 K, A, Seebeck coefficient (S) in (μV/K), B, electrical conductivity scaled by relaxation time (σ/τ) in (1/Ωms), C, electronic component of thermal conductivity scaled by relaxation time (κ ε /τ) in (Wm −1 K −1 s −1 ), D, power factor (S 2 σ/τ) in (10 10 Wm −1 K −1 ) [Colour figure can be viewed at wileyonlinelibrary.com] conductivity with carrier concentration of CH 3 NH 3 PbBr 3 .…”

The role of incident light intensity, wavelength, and exposure time in the modification of conjugated polymer structure in solution

“…1,2,3,4 Through modifications to solution casting techniques and annealing processes, varying degrees of control of active layer domain patterns and sizes can be realized, which ultimately manifest themselves in the form of changes to such crucial device characteristics as exciton dissociation lengths and heterojunction surface areas, morphological facets which have repeatedly proven to be closely tied to effective device effeciencies. 5,6,7,8,9 Given the clear importance of comprehensive control of these organic device functional layer morphologies, exploring and properly developing economically feasible and non-intrusive methods for directing organic layer assembly has become key.…”