Student research opportunities
High-efficiency nano-structured thin film solar cells
Project Code: CECS_880
This project is available at the following levels:
Honours, Masters, PhD
Keywords:
solar cell, efficiency, nano structure, thin film, low cost, pn junction, fabrication, surface lost
Supervisor:
Dr Yuerui (Larry) LuOutline:
Nanostructured silicon thin film solar cells are promising, due to the strongly enhanced light trapping, high carrier collection efficiency, and potential low cost. Ordered nanostructure arrays, with large-area controllable spacing, orientation, and size, are critical for reliable light-trapping and high-efficiency solar cells. Available top-down lithography approaches to fabricate large-area ordered nanostructure arrays are challenging due to the requirement of both high lithography resolution and high throughput. Here, a novel ordered silicon nano-conical-frustum array structure, exhibiting an impressive absorbance over broad band wavelengths by a thickness of only 5 μm, is realized by our recently reported technique radioisotope-powered parallel electron lithography. Moreover, high-efficiency (up to 10.8%) solar cells are demonstrated, using these ordered ultrathin silicon nano-conical-frustum arrays.
Although these nano-structure arrays have high light absorption efficiency, the solar cell efficiency is still less than half of that for bulk crystalline Si solar cells and the open circuit voltage and fill factor are lower too. This is probably due to the high surface recombination losses, which are introduced by the highly enhanced surface area from the nanostructures, although a thin passivation oxide layer was used. Therefore, how to reduce the surface loss through appropriate surface passivation is critical to further enhance the conversion efficiency. In addition, it will be also interesting to transfer the related fabrication techniques to low-cost substrate.
Requirements/Prerequisites
We are looking for highly motivated Ph.D. graduate students who are majoring in applied physics, electrical engineering, mechanical engineering, chemistry, materials science engineering, biomedical engineering, or other closely related areas to join the research team. We always look for dedicated undergraduate or master students to join us, to do creative work in rapidly growing field and generate co-authored publications.
Student Gain
The student will gain exciting research experience in the rapidly growing field of nanotechnology.
Background Literature
Recommended references:
J. Zhu et al., Optical absorption enhancement in amorphous silicon nanowire and nanocone arrays. Nano Letters 9, 279-282 (2008).
Y. Lu, A. Lal, High-efficiency ordered silicon nano-conical-frustum array solar cells by self-powered parallel electron lithography. Nano Letters 10, 4651-4656 (2010).
J. Oh, H.C. Yuan, H. M. Branz, An 18.2%-efficient black-silicon solar cell achieved through control of carrier recombination in nanostructures. Nature Nanotechnology 7, 743-748 (2012).
K. X. Wang, Z. Yu, V. Liu, Y. Cui, S. Fan, Absorption enhancement in ultrathin crystalline silicon solar cells with antireflection and light-trapping nanocone gratings. Nano Letters 12, 1616-1619 (2012).
