MPhil Thesis Presentation
Efficient Light Trapping on Three-Dimensional Substrates for Thin-Film Photovoltaic

by Mr Siu Fung LEUNG

 :  16 Aug 2013 (Fri)
 :  2pm
Venue  :  Room 2463, 2/F (Lifts 25-26), HKUST

Examination Committee
Prof Jianan QU, ECE/HKUST (Chairman)
Prof Zhi Yong FAN, ECE/HKUST (Thesis Supervisor)

Introducing light trapping scheme is one of the typical approaches to harvest incoming photon more efficiently in modern thin-film photovoltaic (TF-PV) device and this is normally realized by texturized front or bottom surface of the solar cell device to enhance light scattering and reduce surface reflection. Conventionally, back surface texture was fabricated by expensive and limited scalability process like lithography and reactive ion etching (RIE). In our works, we have developed nanospike (NSP) array substrate on aluminum by simple, well-established anodization with high scalability. More importantly, we revealed that with proper design of morphology of NSP, light trapping capability and power conversion efficiency are significantly enhanced for solar cell with such texture which are supported by both experiments and simulations.

Optical characterizations have shown that by employing NSP nanostructure, PV thin films demonstrated much improved optical absorption as opposed to the planar control samples over a large wavelength range and incident angle. With special designed nano-imprint assisted anodization, the optimized NSP structure can deliver more than 90% of Air-mass 1.5 global spectrum integrated solar irradiance as compared to ∼ 60% from the planar control sample result in maximum 30% improvement of power conversion efficiency (PCE). By producing more efficient solar cell, the amount of PV materials been used in each solar panel module can be reduced and potentially lower the price of solar energy. This is of great importance for the future development of solar energy. To sum up, we have demonstrated promising potential of nanospike for photovoltaic which can substantially boost the competitiveness of PV over the conventional power generation approaches.
*** ALL ARE WELCOME !! ***