Qinke Shu

Carbon Nanotube Sponges

[*] Prof.D.Wu,X.Gui,Prof. J.Wei.Prof. K.Wang, Prof.H.Zhu, Y. Jia,Q.Shu Key Laboratory for Advanced Materials Processing Technology, Ministry of Education Department of Mechanical Engineering, Tsinghua University Beijing 100084 (P. R. China) E-mail: wdh-dme@tsinghua.edu.cn Prof. A. Cao Department of Advanced Materials and Nanotechnology College of Engineering, Peking University Beijing 100871 (P. R. China) E-mail: anyuan@pku.edu.cn

Graphene/Silicon Nanowire Schottky Junction for Enhanced Light Harvesting

Schottky junction solar cells are assembled by directly coating graphene films on n-type silicon nanowire (SiNW) arrays. The graphene/SiNW junction shows enhanced light trapping and faster carrier transport compared to the graphene/planar Si structure. With chemical doping, the SiNW-based solar cells showed energy conversion efficiencies of up to 2.86% at AM1.5 condition, opening a possibility of using graphene/semiconductor nanostructures in photovoltaic application.

Graphene sheets from worm-like exfoliated graphite

High quality graphene sheets have been prepared by a facile liquid phase exfoliation of worm-like graphite (WEG). This approach combining with the advances in large scale industry manufacturing of WEG could potentially lead to the development of new and more effective graphene products.

Hybrid Heterojunction and Photoelectrochemistry Solar Cell Based on Silicon Nanowires and Double-Walled Carbon Nanotubes

A hybrid solar cell model composed of a heterojunction cell and a photoelectrochemical (PEC) cell has been proposed and characterized. In the hybrid cell, a thin film of double-walled carbon nanotubes forms a heterojunction with the silicon nanowire (SiNW) array and also functions as the transparent counter electrode of the PEC cell. The cell performance can be readily tuned by controlling the SiNW density. Under AM 1.5G illumination, a power conversion efficiency of 1.29%, higher than those reported for SiNW array-based PEC cells, has been obtained.

Large area, highly transparent carbon nanotube spiderwebs for energy harvesting

Carbon nanotubes possess excellent electronic properties, and when self-assembled into thin films, they form conductive and transparent networks that are useful for many applications. Here, we synthesized large-area (100 cm2) spiderwebs consisting of interconnected single-walled nanotubes by floating catalyst chemical vapor deposition and a solvent-induced condensation process. These spiderwebs are sticky and robust, can be directly deposited or transferred to various materials and structures such as metal, paper, texture surface, and micro carbon fibers. The spiderwebs offer tunable transparency in the range up to 95%, and show enhanced conductivity compared with most of previous directly grown or post treatment films. Serving as transparent electrodes of solar cells, the nanotube spiderwebs can extract charge carriers from industrial semiconductors with a power conversion efficiency of 7.3% under AM 1.5 G, 100 mW cm−2 illumination.

Low voltage energy-saving double-walled carbon nanotube electric lamps

The relative efficacy of electric lamps with double-walled carbon nanotube (DWNT) filaments is higher than that with tungsten filaments at the same input power. The luminescence of DWNT electric lamps shows a cold light performance besides blackbody radiation. At a color temperature of 2386 K, the visible light emitted by the DWNT electric lamp (filament diameter: 0.06 mm) occupies 7.6% of the total radiation energy, higher than that of tungsten lamps. The longevity of the DWNT electric lamp (filament diameter: 0.15 mm, 15 V) is no less than 3000 h. DWNT electric lamps are energy saving at low voltages and have potential applications.