Browsing by Author "Lan, Zih-Jian"

Now showing 1 - 3 of 3

Construction of a photoanode with varied TiO2 nanostructures for a Z907-sensitized solar cell with efficiency exceeding 10%
(2014)
Shiu, Jia-Wei
;
Lan, Zih-Jian
;
Chan, Chien-Yi
;
Wu, Hui-Ping
;
Diau, Eric Wei-Guang
For Z907-based dye-sensitized solar cells, we constructed photoanodes, layer by layer, containing titania nanostructures of varied types - spherical nanoparticles (NPs), one-dimensional nanorods (NRs), and octahedron-like nanocrystals of varied size (HD1-HD3), in either a bi-layer (BL) or a multi-layer (ML) film configuration. To understand the kinetics of electron transport in these devices, we measured charge extraction, intensity-modulated photocurrent spectra and photovoltage spectra of devices made of either these nanomaterials or hybrid HD-NP composites (HDP). The HD devices featured an excellent characteristic of electron transport and upward-shifted potentials to produce V-OC greater than those of the NP and NR devices, but the latter featured a larger dye loading to give J(SC) greater than that for the former; the devices fabricated with hybrid HDP films showed enhanced J(SC) and balanced V-OC to perform better than their individual counterparts. We constructed the ML devices based on the NP-BL system with additional HDP layers inserted between the two components, NP and SL, to enhance J(SC) so as to attain the best performance, with efficiency of power conversion (PCE) = 10.1%, at a film thickness (L) of 26 mu m. Because of the robust structural feature of the HD films, the devices fabricated with a simple BL film configuration, HD1/SL = 6/3, exhibited the best performance, PCE = 10.2% at L = 29 mu m, which is a promising advance for Z907-based solar cells with a superior and enduring stability of performance for commercialization.
Highly efficient porphyrin-sensitized solar cells with enhanced light harvesting ability beyond 800 nm and efficiency exceeding 10%
(2014-04-01)
Wang, Chin-Li
;
Hu, Jyun-Yu
;
Wu, Cheng-Hua
;
Kuo, Hshin-Hui
;
Chang, Yu-Cheng
A new porphyrin sensitizer, LD31, was designed based on a donorp- pi-acceptor structure, in which an ethynyl-anthracenyl moiety was inserted between the dioctylaminophenyl group and the porphyrin core in order to extend the p-conjugation of the dye for improved light-harvesting ability. The device made of LD31 exhibited panchromatic spectral features covering the whole visible region and further extending over 800 nm. When combined with an organic dye (AN-4), the performance of the LD31/AN-4 co-sensitized device attained JSC/ mA cm(-2) = 20.3, VOC/mV = 704, FF = 0.72, and the overall efficiency of power conversion eta=10.3%.
Hybrid Titania Photoanodes with a Nanostructured Multi-Layer Configuration for Highly Efficient Dye-Sensitized Solar Cells
(2013-05-02)
Wu, Hui-Ping
;
Lan, Chi-Ming
;
Hu, Jyun-Yu
;
Huang, Wei-Kai
;
Shiu, Jia-Wei
To construct a hybrid titania photoanode containing nanoparticles and nanorods of varied size in a multilayer (ML) configuration for dye-sensitized solar cells, the essence of our ML design is a bilayer system with additional layers of nanorods of well-controlled size inserted between the transparent and the scattering layers to enhance the light harvesting capability for photosensitizers with small absorptivity, such as Z907. We measured charge-extraction and intensity-modulated photoelectric spectra to show the advantages of one-dimensional nanorods with an improved electron-transport property and an upward shift of the potential band edge; a favorable ML configuration was constructed to have a cascade potential feature for feasible electron transport from long nanorods, to normal nanorods, to small nanoparticles. On the basis of the ML system reported herein, we demonstrate how the performance of a Z907 device is improved to attain eta similar to 10%, which is a milestone for its future commercialization.