Fan Bai

Bio: Fan Bai is an academic researcher from North China Electric Power University. The author has contributed to research in topics: Silicon & Etching (microfabrication). The author has an hindex of 14, co-authored 32 publications receiving 471 citations. Previous affiliations of Fan Bai include Harbin Institute of Technology.

Facile fabrication of MoS2/PEDOT–PSS composites as low-cost and efficient counter electrodes for dye-sensitized solar cells

Abstract: A novel MoS 2 /PEDOT–PSS counter electrode (CE) is proposed and used for dye sensitized solar cells (DSCs). The MoS 2 /PEDOT–PSS composites were facilely obtained from the mechanical mixture of hydrothermal synthesized MoS 2 nanomaterial and poly(3,4-ethylenedioxythiophene)–poly(styrenesulfonate) (PEDOT–PSS) aqueous solution, and the composites are compatible to low temperature and cost-effective screen-printing fabrication technique. DSC with MoS 2 /PEDOT–PSS CE exhibits comparable power conversion efficiency and fill factor to the DSC with conventional Pt CE. The good photovoltaic performance of DSC using MoS 2 /PEDOT–PSS CE is primarily derived from the high electrocatalytic activity of nanosized MoS 2 and the high conductive feature of PEDOT–PSS. These results reveal the potential application of MoS 2 /PEDOT–PSS composite in the use of low-cost, printable and efficient Pt-free CEs.

Effective light trapping enhancement by plasmonic Ag nanoparticles on silicon pyramid surface

Abstract: Plasmonic Ag nanoparticles were deposited on the silicon pyramid structures to further reduce surface reflectance. Compared with the bare silicon pyramid surface, a dramatic reflectance reduction around 380 nm was observed and the weighted average surface reflectance from 300 nm to 1100 nm could be reduced about 3.4%. By a series of designed experiments combined with Mie theory calculations, the influences of the size, shape and density distribution of Ag nanoparticles on the surface reflectance reduction were investigated in detail. This study shows a practicable method to improve light trapping for the application to solar cells.

A one-step template-free approach to achieve tapered silicon nanowire arrays with controllable filling ratios for solar cell applications

Abstract: A facile and low-cost one-step template-free approach is presented for the fabrication of tapered silicon nanowire (SiNW) arrays. A silver network catalyst is used to chemically etch silicon in a HF/H2O2 solution, where the solution is chosen to selectively dissolve the silver network during the etching process, resulting in the formation of tapered SiNWs. Notably, the filling ratio of the tapered SiNWs can be tuned simply by varying the pattern of the silver network. Surface reflection was strongly suppressed in the tapered SiNW arrays (only 400 nm in thickness), which were employed in SiNWs/poly(3,4-ethylenedioxy-thiophene):poly(styrenesulfonate) (PEDOT:PSS) heterojunction solar cells exhibiting a power conversion efficiency of 6.7%. The tapered SiNW arrays prepared by this one-step template-free method are expected to be efficient structures for a variety of photovoltaic devices.

Review on application of PEDOTs and PEDOT:PSS in energy conversion and storage devices

Abstract: Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is the most successful conducting polymer in terms of practical application. It possesses many unique properties, such as good film forming ability by versatile fabrication techniques, superior optical transparency in visible light range, high electrical conductivity, intrinsically high work function and good physical and chemical stability in air. PEDOT:PSS has wide applications in energy conversion and storage devices. This review summarizes its applications in organic solar cells, dye-sensitized solar cells, supercapacitors, fuel cells, thermoelectric devices and stretchable devices. Approaches to enhance the material/device performances are highlighted.

Surface and Interface Engineering of Electrode Materials for Lithium‐Ion Batteries

Abstract: Lithium-ion batteries are regarded as promising energy storage devices for next-generation electric and hybrid electric vehicles. In order to meet the demands of electric vehicles, considerable efforts have been devoted to the development of advanced electrode materials for lithium-ion batteries with high energy and power densities. Although significant progress has been recently made in the development of novel electrode materials, some critical issues comprising low electronic conductivity, low ionic diffusion efficiency, and large structural variation have to be addressed before the practical application of these materials. Surface and interface engineering is essential to improve the electrochemical performance of electrode materials for lithium-ion batteries. This article reviews the recent progress in surface and interface engineering of electrode materials including the increase in contact interface by decreasing the particle size or introducing porous or hierarchical structures and surface modification or functionalization by metal nanoparticles, metal oxides, carbon materials, polymers, and other ionic and electronic conductive species.

Exceeding the limit of plasmonic light trapping in textured screen-printed solar cells using Al nanoparticles and wrinkle-like graphene sheets

Abstract: The solar cell market is predominantly based on textured screen-printed solar cells. Due to parasitic absorption in nanostructures, using plasmonic processes to obtain an enhancement that exceeds 2.5% of the short-circuit photocurrent density is challenging. In this paper, a 7.2% enhancement in the photocurrent density can be achieved through the integration of plasmonic Al nanoparticles and wrinkle-like graphene sheets. For the first time, we experimentally achieve Al nanoparticle-enhanced solar cells. An innovative thermal evaporation method is proposed to fabricate low-coverage Al nanoparticle arrays on solar cells. Due to the ultraviolet (UV) plasmon resonance of Al nanoparticles, the performance enhancement of the solar cells is significantly greater than that from Ag nanoparticles. Subsequently, we deposit wrinkle-like graphene sheets over the Al nanoparticle-enhanced solar cells. Compared with planar graphene sheets, the bend carbon layer also exhibits a broadband light-trapping effect. Our results exceed the limit of plasmonic light trapping in textured screen-printed silicon solar cells. The performance of screen-printed silicon solar cells can be enhanced by aluminium nanoparticles. Xi Chen and co-workers from the Swinburne University of Technology in Australia report that light scattering effects can increase a solar cell’s short-circuit photocurrent density by up to 6.3%. Aluminium nanoparticles are advantageous because their Fano resonance, unlike those of gold or silver nanoparticles, falls in the ultraviolet wavelength band. This means that detrimental Fano interference effects between scattered and unscattered light can be avoided within the solar cell’s spectral range of operation. The addition of wrinkle-like graphene sheets further improves the photocurrent to 7.3% beyond that of an unmodified screen-printed cell.

Review of porous silicon preparation and its application for lithium-ion battery anodes

Abstract: Silicon is of great interest for use as the anode material in lithium-ion batteries due to its high capacity. However, certain properties of silicon, such as a large volume expansion during the lithiation process and the low diffusion rate of lithium in silicon, result in fast capacity degradation in limited charge/discharge cycles, especially at high current rate. Therefore, the use of silicon in real battery applications is limited. The idea of using porous silicon, to a large extent, addresses the above-mentioned issues simultaneously. In this review, we discuss the merits of using porous silicon for anodes through both theoretical and experimental study. Recent progress in the preparation of porous silicon through the template-assisted approach and the non-template approach have been highlighted. The battery performance in terms of capacity and cyclability of each structure is evaluated.