Shuyi Cheng

Study and enhance the photovoltaic properties of narrow-bandgap Cu2SnS3 solar cell by p–n junction interface modification

Photovoltaic properties of narrow-bandgap Cu(2)SnS(3) (CTS) are studied for the first time by employing a superstrate solar cell structure of fluorine-doped tin oxide (FTO) glass/TiO(2)/In(2)S(3)/CTS/Mo. The structural, optical, and electronic characteristics of the CTS make it great potential as bottom cell absorber material for low-cost thin film tandem solar cell application. Furthermore, by inserting a thin low temperature deposited In(2)S(3) layer between the In(2)S(3) buffer layer and the CTS absorber layer, an enhancement in the performance of the solar cell can be achieved, leading to about 75% improvement (η=1.92%) over the unmodified device (η=1.10%).

Printed ethyl cellulose/CuInSe2 composite light absorber layer and its photovoltaic effect

A novel ethyl cellulose/CuInSe2 (CISe) composite light absorber layer and its photovoltaic effect are reported. The precursor absorber layer was deposited from screen printing paste containing ethyl cellulose and CISe powder, and was followed by rapid thermal annealing. Experimental results indicated that the ethyl cellulose remained in the annealed absorber layer, and the composite absorber layer may consist of ethyl cellulose/CISe composite shell/core structure. The structural, optical and electronic properties of the composite absorber layer were fully investigated. The composite absorber layer shows photovoltaic efficiency of 0.65% under standard test condition.

Is pulsed electric field still effective for RNA separation in capillary electrophoresis

Pulsed field capillary electrophoresis (PFCE) is a predominant technique to cope with difficulties in resolving large DNA strands, yet it is still unclear whether pulsed electric field is effective for the separation of higher mass RNA. In this paper we focused on the role of pulsed electric field in large RNA fragments analysis by comparing RNA separation performance in PFCE with that in constant field CE. Separation performance in terms of migration mobility, plate numbers, resolution, and selectivity has been tested for the analysis of RNA from 0.1 to 10.0 kilo nucleotide (knt) under different electrophoretic conditions. Denaturation, important to obtain uniform and identifiable peaks, was accomplished by heating the sample in 4.0M urea prior to analysis and the presence of 4.0M urea in the electrophoresis buffer. Results demonstrate that unlike DNA in PFCE, the pulsed electric field mainly affects the separation performance of RNA between 0.4 and 2.0 knt. The migration mobility of long RNA fragments is not a strong function of modulation depth and pulsed frequency. Moreover, the logarithm of RNA mobility is almost inversely proportional to the logarithm of molecule size up to 6.0 knt with correlation coefficient higher than 0.99 in all the polymer concentrations measured here. Resonance frequency of RNA in PFCE was also observed. While these initial experiments show no distinct advantages of using PFCE for RNA separation, they do take further step toward characterizing the migration behavior of RNA under pulsed field conditions.

Design of separation length and electric field strength for high-speed DNA electrophoresis

Gel‐based DNA separation on microchip will play an important role in future genomic analysis due to its potential for high‐efficiency and high‐speed. Optimal design of microchip and separation condition is essential to take full advantage of high‐speed separation on microchip. Separation length L and electric field strength E, which are crucial for design of microchip system, are focused on in this paper. Simultaneous optimization of L and E was carried out to achieve the most rapid separation. It was shown that the condition of L and E and the shortest separation time is closely related to the shape of resolution Rs surface in a three‐dimensional space with axes E, L, and Rs. This surface was investigated, taking sample injection, detector, diffusion, and Joule heating into account. Thermal gradient broadening due to Joule heating helps to produce camber or ridge shape of Rs surface, which is essential for the shortest separation length and separation time. Sample plug length and detection volume should be more carefully controlled in microchip. The property of diffusion coefficient was shown to play a key role in determining Rs surface.

The effect of electrophoretic parameters on separation performance of short DNA fragments

Effective separation of short DNA fragments is important for the identification of PCR or LAMP products. We investigated the effect of electric field strength, sample plug width, effective length of the capillary, concentration and molecular weight of polymer on the separation performance of small DNA. Results demonstrated that the sample plug played a non-negligible role in the peak broadening. The migration time of DNA was exponentially decreased with the increase of electric field strength. Increasing effective length of capillary, concentration or molecular weight of HEC may improve the separation performance, but it was at the cost of long migration time.