Influence of PEDOT:PSS Doping on the Performance of Organic Solar Cells

Fabrication of Organic Solar Cells (OSC) using PEDOT:PSS, has been focussed on the formation of the four-layered configuration of : ITO / PEDOT:PSS / P3TH:PC60 BM / LiF with Al metal layers its electrode. The active layer comprised P3TH:PC60 BM, where P3HT formed the donor and PC60 BM the acceptor components. Interestingly, it has been observed that the OSCs fabricated from ethylene glycol doped PEDOT:PSS depicted Power Conversion Efficiency (PCE) of about 2 times more than that of OSCs made from pure PEDOT:PSS. After optimizing process parameters(~ 16% of DMF, ~10% of DMSO, and ~ 12% EG in PEDOT:PSS) and continued loading of doped components, the conductivity reflected a decreasing trend. Such a phenomenon was attributed to an increasing distance between the successive conductive grain/domain, which has been explained based on Atomic Force Microscopy (AFM). Moreover, stress has been made on the inter-junction behavior of carrier transport, particularly the hole conduction mechanism. Further, the perovskite-based solar cell has been compared and discussed to understand material behavior and device performance better.

Deconvolution of local activation energy of hopping conductivity: Application to p-Ge

A new method for analyzing the local reduced activation energy [Formula: see text] of the impurity conductivity is applied to Ga-doped [Formula: see text]-Ge samples with a constant compensation ratio of [Formula: see text] reported by Zabrodskii and Andreev [Int. J. Mod. Phys. B 8, 883 (1994)]. Here, the local reduced activation energy is defined as [Formula: see text], where [Formula: see text] and [Formula: see text] denote conductivity and absolute temperature, respectively. The method enables us to deconvolute the [Formula: see text] curve into contributions from different conduction mechanisms such as free-hole conduction, nearest-neighbor hopping (NNH) conduction and variable-range hopping (VRH) conduction. As a result, it is shown that both the power exponents of the pre-exponential factors of NNH and VRH conductivity tend to decrease with increasing impurity concentration.

Improved polaronic transport under a strong Mott–Hubbard interaction in Cu-substituted NiO

We report the origin of improved hole conduction without band-gap collapse in Cu-doped NiO.