Numerical Approach to the Investigation of Performance of Silicon Nanowire Solar Cells Embedded in a SiO2 Matrix

The electrical characteristics of silicon nanowire (SiNW) solar cells with p-type hydrogenated amorphous silicon oxide ($E_{\text{g}} = 1.9$ eV)/n-type SiNWs embedded in a SiO 2 /n-type hydrogenated amorphous silicon oxide ($E_{\text{g}} = 1.9$ eV) structure have been investigated using two- and thr...

Full description

Saved in:
Bibliographic Details
Published inJpn J Appl Phys Vol. 51; no. 11; pp. 11PE12 - 11PE12-4
Main Authors Kurokawa, Yasuyoshi, Kato, Shinya, Watanabe, Yuya, Yamada, Akira, Konagai, Makoto, Ohta, Yoshimi, Niwa, Yusuke, Hirota, Masaki
Format Journal Article
LanguageEnglish
Published The Japan Society of Applied Physics 01.11.2012
Online AccessGet full text

Cover

More Information
Summary:The electrical characteristics of silicon nanowire (SiNW) solar cells with p-type hydrogenated amorphous silicon oxide ($E_{\text{g}} = 1.9$ eV)/n-type SiNWs embedded in a SiO 2 /n-type hydrogenated amorphous silicon oxide ($E_{\text{g}} = 1.9$ eV) structure have been investigated using two- and three-dimensional device simulators, taking into account the quantum size effect. The average bandgap of a SiNW embedded in SiO 2 increased from 1.15 to 2.68 eV with decreasing diameter from 10 to 2 nm, owing to the quantum size effect. Note that under sunlight of AM1.5G, the open-circuit voltage ($V_{\text{oc}}$) of SiNW solar cells also increased to 1.46 V with decreasing diameter of the SiNWs to 2 nm. This result suggests that it is possible to enhance $V_{\text{oc}}$ by applying the quantum size effect, and a SiNW is a promising material for all-silicon tandem solar cells.
Bibliography:(a) Schematic diagram of SiNW solar cells for electrical properties based on two-dimensional simulation. (b) Calculation model for Schrödinger--Poisson method in three-dimensional simulation. (a) Average bandgap of SiNWs calculated by solving the Schrödinger equations and by the BQP method. (a, inset) Band diagrams corresponding to the cross section (i) of SiNW solar cells in Fig. (a) taking and not taking into account the quantum effect. The diameter of SiNWs is 2 nm. (b) Average quantum potentials for electrons and holes along the dashed line (ii) in Fig. (a). (a) Dependences of the diameter of SiNWs on open-circuit voltage of the SiNW solar cells and the average bandgap of the SiNWs. (b) Relationship between electric field in the SiNW on cross section (ii) in Fig. (a) and the diameter of SiNWs.
ISSN:0021-4922
1347-4065
DOI:10.1143/JJAP.51.11PE12