Crystalline silicon (c-Si) is not used for developing transparent photovoltaics, owing to its opaque nature. Furthermore, adding optical transparency to a conventional c-Si wafer is one of the most challenging problems in this field. Here, we demonstrate the development of a neutral-colored transparent c-Si substrate using a 200-μm-thick c-Si wafer, which is known to be intrinsically opaque. Transparent c-Si substrates were fabricated by placing microhole-shaped light transmission windows on a bare c-Si wafer. These windows were designed to enable the transmission of all incident visible light through the substrate, resulting in a colorless substrate. A light absorption area was also designed on the wafer to efficiently absorb incident light. As a representative application, solar cells fabricated using the neutral-colored transparent c-Si substrate showed a power conversion efficiency of up to 12.2%. Therefore, our transparent c-Si solar cells present a unique opportunity to develop next-generation colorless transparent photovoltaics. Transparent solar cells are attractive energy conversion devices because they can be used in various applications in our daily life, such as building-integrated photovoltaics. However, transparent solar cells developed to date have limitations in efficiency and stability. Crystalline silicon (c-Si) is one of the best candidates to develop transparent solar cells with high efficiency and stability, because conventional c-Si solar cells are known to exhibit high efficiency and long-term stability compared with other solar cells. However, the opaque characteristic of the c-Si wafer hinders the development of transparent solar cells using c-Si. Here, we present a novel approach to develop neutral-colored transparent c-Si solar cells that exhibit the highest efficiency among neutral-colored transparent solar cells developed to date. Furthermore, we believe that this study makes a significant contribution not only to the field of photovoltaics but also to various transparent electronics. We report a neutral-colored transparent c-Si substrate using a 200-μm-thick c-Si wafer, which is known to be opaque. The transparent c-Si substrate shows a completely neutral color, similar to glass without a transmission cut-on wavelength. In addition, the transmittance of the transparent c-Si substrate is systematically tuned under the full solar spectrum. As a representative application, the transparent solar cells fabricated with the substrate developed in this study show a power conversion efficiency of up to 12.2%.
Bibliographical noteFunding Information:
The New Renewable Energy Core Technology Development Project of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) granted financial resources from the Ministry of Trade, Industry & Energy, Republic of Korea (no. 20183010013900). It was also supported by the National Research Foundation of Korea (NRF) grant funded by the Korean Government (MSIP) (NRF-2019R1A2C2086602) and the KU-KIST school project. K.S. conceived the idea. K.L. N.K. H.-D.U. and K.S. designed the experiment. K.L. N.K. W.J. D.C. and J.P. carried out the device fabrication, photovoltaic characterization, and analysis. K.L. N.K. and K.J.P. carried out the optical microscope imaging and transmission spectra measurement. K.K. and S.L. performed theoretical analysis including Shockley-Queisser limit and numerical simulations (i.e. FDTD and FEM). All authors contributed to the discussion and interpretation of the results and completion of the manuscript. The authors declare no competing interests.
© 2019 Elsevier Inc.
- crystalline silicon
- neutral color
- solar cell
- transparent photovoltaics
ASJC Scopus subject areas