Enhancing the light absorbance of polymer solar cells by introducing pulsed laser-deposited CuIn0.8Ga0.2Se2 nanoparticles.

Yu Zhao,Lei-Lei Guan,Jia-Da Wu,Zhi-Feng Ying,Yan-Li Li,Ning Xu,Jian Sun,Hui Li,Xu-Jun Liu

doi:10.1186/1556-276x-9-308

Abstract

Evenly separated crystalline CuIn0.8Ga0.2Se2 (CIGS) nanoparticles are deposited on ITO-glass substrate by pulsed laser deposition. Such CIGS layers are introduced between conjugated polymer layers and ITO-glass substrates for enhancing light absorbance of polymer solar cells. The P3HT:PCBM absorbance between 300 and 650 nm is enhanced obviously due to the introduction of CIGS nanoparticles. The current density-voltage curves of a P3HT:PCBM/CIGS solar cell demonstrate that the short-circuit current density is improved from 0.77 to 1.20 mA/cm2. The photoluminescence spectra show that the excitons in the polymer are obviously quenched, suggesting that the charge transfer between the P3HT:PCBM and CIGS occurred. The results reveal that the CIGS nanoparticles may exhibit the localized surface plasmon resonance effect just as metallic nanostructures.PACS61.46. + w; 61.41.e; 81.15.Fg; 81.07.b

Highlights

In recent years, polymer-fullerene-based bulk heterojunction (BHJ) solar cells aroused the interest of researchers and manufacturers due to their low cost, large areas, and flexibility [1,2,3]
The calculated grain size is some smaller than that shown in Figure 3a, the CIGS(112) peak should be induced by the CIGS nanoparticles observed by scanning electron microscopy (SEM) for defects, dislocations, and twins in the grains can lead to smaller calculated grain size than that of the actual one
The CIGS nanoparticles with sizes of 20 to 70 nm and a distribution density of about 7 × 109 cm−2 were deposited on the ITO-glass substrates by pulsed laser deposition (PLD)

Summary

Introduction

Polymer-fullerene-based bulk heterojunction (BHJ) solar cells aroused the interest of researchers and manufacturers due to their low cost, large areas, and flexibility [1,2,3]. Compared with crystalline silicon cells, the efficiency of polymer-fullerene BHJ solar cells is still much lower. One of the main factors limiting their efficiency is the low light absorption and low charge carrier mobility of polymer absorbers. The poly(3hexylthiophene) (P3HT) mixed with phenyl-C61-butyric acid methyl ester (PCBM), a commonly used conjugated polymer absorber in polymer-fullerene BHJ solar cells, has quite a large bandgap of about 2.1 eV, determining that it can only absorb the incident light whose wavelength is shorter than 590 nm. The CIGS is potential for use as inorganic absorbers in the hybrid solar cells

Methods

Results

Conclusion