# Tailored NaCl Doping of PEDOT:PSS as a Hole Transport Layer for Flexible Air-Blade-Coated Devices

## TL;DR

This paper shows how adding small amounts of salt to a material improves the performance of flexible solar cells.

## Contribution

The study reveals that low NaCl doping enhances photovoltaic performance by improving molecular organization and electronic properties of PEDOT:PSS.

## Key findings

- Low NaCl concentrations improve photovoltaic metrics like voltage and efficiency.
- Post-annealing enhances performance, especially in low NaCl samples.
- NaCl doping modifies PEDOT:PSS structure, improving light transmission and energy efficiency.

## Abstract

Organic photovoltaic devices hold significant promise
for sustainable
energy generation, due to their low manufacturing cost and benefits
such as lightness, semitransparency, and flexibility. This study explores
the experimental and theoretical study of the effects of sodium chloride
(NaCl) doping on PEDOT:PSS, with a focus on its photovoltaic properties
in inverted all air blade-coated devices. By varying NaCl concentrations,
we analyze key performance metrics and annealing treatment, open-circuit
voltage, short-circuit current density, fill factor, and power conversion
efficiency. The results indicate that lower concentrations of NaCl
substantially improve these parameters, while higher concentrations
can impair the efficiency of the device. Post annealing was found
to improve photovoltaic performance, especially in samples with low
NaCl concentrations. Advanced characterization techniques, including
atomic force microscopy, Raman spectroscopy, and scanning electron
microscopy, revealed that doping with NaCl improves the molecular
organization of PEDOT:PSS, leading to better light transmission and
energy efficiency. Theoretical results indicate that NaCl interacts
with the thiophene rings of PEDOT:PSS, modifying its electronic and
structural properties. These results highlight the fundamental role
of doping and processing conditions in optimizing the performance
of organic solar cells, providing valuable information for the development
of efficient, economical, and sustainable photovoltaic technologies.