Performance improvement of inverted bulk heterojunction solar cells by use of gold nanoparticles modified PEDOT: PSS as an anode buffer layer

Abstract

We investigate the effect of gold nanoparticles capped by Citrate (Au-CA) and 3-MPA (Au-MPA) addition into PEDOT:PSS as an anode buffer layer (ABL) in the structure of an inverted hybrid solar cell. The localized surface plasmon resonance (LSPR) excited in AuNP is expected to accelerate the transfer of holes to the anode (Ag), increasing the mobility of charge carriers in this type of solar cell. The measured UV–visible absorption spectra show typical representation of the PEDOT:PSS mixtures, which changed due to modification of Au-NP’s concentrations. The maximum absorption peak of Au-CA solution ([Formula: see text][Formula: see text]nm) is located around 522[Formula: see text]nm, while Au-MPA solution ([Formula: see text][Formula: see text]nm) is located around 528[Formula: see text]nm. These peaks are found to be red-shifted including the absorbance intensity increased when they are modified with that of PEDOT:PSS. Under the illumination of 100[Formula: see text]mW/cm2 simulated solar irradiation, the fabricated solar cell device exhibits an increase of Power Conversion Efficiency (PCE) value from 1.02% to 2.38% for the device with the addition of 20.0[Formula: see text]v/v% Au-CA and to 2.44% for the device with the addition of 2.0[Formula: see text]v/v% of Au-MPA. In our case, the enhancement of open circuit voltage ([Formula: see text]) and short circuit current density ([Formula: see text]) together occurs as a result of localized electric field effects from AuNP that influence charge transport and also the work function at the interface between PEDOT:PSS and the Ag-electrode. In our result, the fabricated solar cell with the addition of Au-MPA into the device structure shows a better performance efficiency of about 2.44% in comparison to the device with the addition of Au-CA of about 2.38%.