| AVS 59th Annual International Symposium and Exhibition | |
| Energy Frontiers Focus Topic | Monday Sessions |
| Session EN+NS-MoM |
| Session: | Nanostructured Solar Cells |
| Presenter: | G. Uchida, Kyushu University, Japan |
| Authors: | G. Uchida, Kyushu University, Japan H. Seo, Kyushu University, Japan Y. Wang, Kyushu University, Japan K. Kamataki, Kyushu University, Japan N. Itagaki, Kyushu University, Japan K. Koga, Kyushu University, Japan M. Shiratani, Kyushu University, Japan |
| Correspondent: | Click to Email |
The pressing need for massively scalable carbon-free energy sources has focused attention on both increasing the efficiency and decreasing the cost of solar cells. Quantum-dot (QD) solar cells employing multiple exciton generation (MEG) have attracted much attention as a candidate for the third generation solar cells, because MEG represents a promising route to increased solar conversion efficiencies up to about 44 % in single junction. Our interest has been concerned with QD sensitized solar cells using Si nanoparticles [1]. The main purpose of this study is to discuss the characteristic of the quantum yield in view of the MEG effect.
QD thin films composed of size-controlled Si nanoparticles were deposited using double multi-hollow discharge plasma chemical vapour deposition (CVD) of a SiH4/H2 and CH4 or N2 gas mixture [2]. Short-circuit current density of Si QD sensitized solar cells increases by a factor of 2.5 by irradiation of CH4 or N2 plasma to Si nanoparticle surface. We also have measured incident photon-to-current conversion efficiency (IPCE) in the near-ultraviolet range using quartz-glass plates as front panels of QD sensitized solar cells. IPCE gradually increases by light irradiation in a wavelength range less than 600 nm around optical band-gap (Eg) of Si nanoparticle films, and then steeply increases below 280 nm around 2Eg. This rapid increase of IPCE under the ultraviolet light incidence may be explained by the theoretically predicted MEG, the creation of two electron-hole pairs from one high-energy photon incidence, in Si nanoparticle QDs.
[1] G. Uchida, et al., Phys. Status Solidi C 8 (2011) 3021.
[2] G. Uchida, et al., Jpn. J. Appl. Phys. 51 (2011) 01AD01-1.