Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2016 Jan 20:7:75-80.
doi: 10.3762/bjnano.7.9. eCollection 2016.

Dependence of lattice strain relaxation, absorbance, and sheet resistance on thickness in textured ZnO@B transparent conductive oxide for thin-film solar cell applications

Kuang-Yang Kou  1 , Yu-En Huang  2 , Chien-Hsun Chen  3 , Shih-Wei Feng  2
Affiliations

Dependence of lattice strain relaxation, absorbance, and sheet resistance on thickness in textured ZnO@B transparent conductive oxide for thin-film solar cell applications

Kuang-Yang Kou et al. Beilstein J Nanotechnol. .

Abstract

The interplay of surface texture, strain relaxation, absorbance, grain size, and sheet resistance in textured, boron-doped ZnO (ZnO@B), transparent conductive oxide (TCO) materials of different thicknesses used for thin film, solar cell applications is investigated. The residual strain induced by the lattice mismatch and the difference in the thermal expansion coefficient for thicker ZnO@B is relaxed, leading to an increased surface texture, stronger absorbance, larger grain size, and lower sheet resistance. These experimental results reveal the optical and material characteristics of the TCO layer, which could be useful for enhancing the performance of solar cells through an optimized TCO layer.

Keywords: absorbance; low-pressure chemical vapor deposition; strain relaxation; textured ZnO; transparent conductive oxide.

PubMed Disclaimer

Figures

Figure 1
Figure 1
AFM images (5 × 5 μm) of (a) c-20 (16.603 nm), (b) c-40 (26.756 nm), (c) c-60 (51.531 nm), and (d) c-70 (56.233 nm) ZnO@B samples. The surface roughness of each sample is given in the parentheses.
Figure 2
Figure 2
SEM images of the (a) c-20, (b) c-40, (c) c-60, and (d) c-70 ZnO@B samples and the panchromatic CL images (e), (f), (g), and (h), respectively, taken over the same regions with 11 kV excitation electron voltage at RT.
Figure 3
Figure 3
Cross-sectional SEM images of the (a) c-20, (b) c-40, (c) c-60, and (d) c-70 ZnO@B samples. The thickness of each sample is shown in the image.
Figure 4
Figure 4
CL spectra of the (a) c-20, (b) c-40, (c) c-60, and (d) c-70 ZnO@B samples for excitations of 5, 7, 9, and 11 kV at RT.
Figure 5
Figure 5
Absorbance (squared) of the four ZnO@B samples.
Figure 6
Figure 6
Raman scattering spectra of the four ZnO@B samples. The spectra display A1(TO) and A1(LO) modes for ZnO. The dotted lines at 379 cm−1 and 574 cm−1 show the strain-free A1(TO) and A1(LO) modes, respectively, for ZnO [20].
Figure 7
Figure 7
In-plane strain for the four ZnO@B samples as a function of ZnO thickness.
See this image and copyright information in PMC

References

    1. Morkoç H, Özgür Ü. Zinc Oxide: Fundamentals, Materials and Device Technology. Weinheim, Germany: Wiley-VCH; 2007. - DOI
    1. Özgür Ü, Alivov Ya I, Liu C, Teke A, Reshchikov M A, Doğan S, Avrutin V, Cho S J, Morkoç H. J Appl Phys. 2005;98:041301. doi: 10.1063/1.1992666. - DOI
    1. Lai C M, Huang Y E, Kou K Y, Chen C H, Tu L W, Feng S W. Appl Phys Lett. 2015;107:022110. doi: 10.1063/1.4926978. - DOI
    1. Söderström T, Dominé D, Feltrin A, Despeisse M, Meillaud F, Bugnon G, Boccard M, Cuony P, Haug F J, Faÿ S, et al. Proc SPIE. 2010;7603:76030B. doi: 10.1117/12.843511. - DOI
    1. Chen X L, Liu J M, Ni J, Zhao Y, Zhang X D. Appl Surf Sci. 2015;328:193–197. doi: 10.1016/j.apsusc.2014.12.018. - DOI

LinkOut - more resources