PEDOT:PSS as an Alternative Hole Selective Contact for ITO-Free Hybrid Crystalline Silicon Solar Cell

Abstract

Organic-inorganic hybrid solar cells were fabricated by spin coating of conductive polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as hole selective contact upon textured n-type crystalline silicon wafers. Two different PEDOT:PSS commercial products (Clevios HTL Solar and PH1000) were compared, enhancing their conductivity and wettability by addition of dimethyl sulfoxide cosolvent and Capstone FS-31 surfactant. Transmission line measurements (TLM) revealed that the sheet resistance of the PEDOT:PSS layer was comparable with that of conventional Indium-Tin oxide (ITO) electrodes, allowing its use as a conductive transparent layer in an ITO-free solar cell. Quasi-steady-state photoconductance measurements revealed an implied open-circuit voltage of 644 mV for HTL Solar, which is equivalent to a saturation current density of 255 fA/cm 2 . In general, the performance of HTL Solar was better than PH1000, exhibiting power conversion efficiency (1 × 1 cm 2 cell area) of 11.6%, as compared with 8.5%.Index Terms-Crystalline silicon (c-Si), hole selective contact, hybrid solar cell, poly(3, 4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS).

Effects of Co-Solvents on the Performance of PEDOT:PSS Films and Hybrid Photovoltaic Devices

“…All wafers were cleaned following the procedures described by Opila and Teplyakov et al: the substrates were cleaned using a Piranha etch (H 2 SO 4 :H 2 O 2 = 4:1) for 5 min, followed by a 5-min DI water rise and a 2-min immersion in hydrofluoric acid (HF, 2 wt%) [10]. After cleaning, the substrates were quickly dried by blowing nitrogen and immediately placed in the passivation solution of benzoquinone (BQ) and methanol (MeOH) [9].…”

“…In the case of the devices presented in this work, the major limiting loss factor was initially assumed to be the resistance of the Ag/PEDOT:PSS interface. Mahato et al performed a contact resistivity measurement for Ag thermally deposited on PEDOT:PSS films (Clevious PH 1000, with a 5 wt% DMSO cosolvent and 0.1% Capstone FS-31 fluoro-surfactant) on planar glass substrates and found contact resistivities of 0.79 Ohm•cm 2 [10]. Such large contact resistivities would make this interfacial resistance the largest source of power loss in the design of a front contact shadow mask.…”

PEDOT:PSS in Water and Toluene for Organic Devices—Technical Approach

“…In recent years, poly(3,4-ethylenedioxythiophene:poly(styrenesulfonate) (PEDOT:PSS), especially with regard to its use in electronic devices including photovoltaics, received interest on account of its relatively simple processability at low temperature, antireflecting properties, and water-based dispersion [24][25][26][27]. In some devices, water-free PEDOT:PSS is required, mainly due to the design of the layer deposition process via evaporation from toluene solution or the vulnerability of some components to moisture, i.e., in the construction of perovskite solar cells [28][29][30].…”

Composition analysis of two different PEDOT:PSS commercial products used as an interface layer in Au/n-Si Schottky diode

“…Subsequently contact angle of HTL Solar is less due to the excess of PSS content. 19 Therefore HTL Solar product could be uniformly deposit on hydrophobic silicon surface in a large area without using any surfactant. 3.1.2 SEM and AFM.…”