Publications de Hoi Nok Tsao | EPFL Graph Search

Optoelectronic and/or electrochemical learning device

The present invention concerns photoelectronic and/or optoelectronic learning device and/or memory device. In an embodiment, the device is a dye- sensitized solar cell. The short circuit photocurrent density (Jsc) of the device, and wherein a degree of a J ...

2018

A Stable Blue Photosensitizer for Color Palette of Dye-Sensitized Solar Cells Reaching 12.6% Efficiency

Shaik Mohammed Zakeeruddin, Yiming Cao, Hoi Nok Tsao

2018

Organic dyes containing fused acenes as building blocks: Optical, electrochemical and photovoltaic properties

Peng Gao, Joël Teuscher, Hoi Nok Tsao

2018

Illumination Time Dependent Learning in Dye Sensitized Solar Cells

Michael Graetzel, Hoi Nok Tsao

Learning through vision is an essential skill for intelligent machines. In an attempt to implement this highly complex feature at low energy cost, a dye-sensitized solar cell is proposed that learns using illumination time as a cue. Particularly, the devic ...

AMER CHEMICAL SOC2018

Enhancing the Stability of Porphyrin Dye-Sensitized Solar Cells by Manipulation of Electrolyte Additives

Michael Graetzel, Paul Joseph Dyson, Shaik Mohammed Zakeeruddin, Chenyi Yi, Hoi Nok Tsao, Pui Shan Genevieve Lau

The use of porphyrin-based photosensitizers with superior light-harvesting properties has enabled the power conversion efficiency of dye-sensitized solar cells (DSCs) to reach 13% under full sun illumination. However, a major limitation of such devices cor ...

Wiley-V C H Verlag Gmbh2015

Redox couple for electrochemical and optoelectronic devices

Michael Graetzel, Mohammad Khaja Nazeeruddin, Shaik Mohammed Zakeeruddin, Jun Ho Yum, Aswani Yella, Hoi Nok Tsao

The present invention provides an improved redox couple for electrochemical and optoelectronic devices. The redox couple is based on a complex of a first row transition metal, said complex containing at least one mono-, bi-, or tridentate ligand comprising ...

2014

Extended pi-Bridge in Organic Dye-Sensitized Solar Cells: the Longer, the Better?

Michael Graetzel, Mohammad Khaja Nazeeruddin, Chenyi Yi, Peng Gao, Hoi Nok Tsao

The elongation of pi-conjugated bridges between the donor (D) and the acceptor (A) represents a feasible strategy towards enhancement of light-harvesting in both breadth and depth of organic D-pi-A dyes suitable for nanocrystalline TiO2-based dye-sensitize ...

Wiley-VCH Verlag Berlin2014

Highly Stable Dye-Sensitized Solar Cells Based on Novel 1,2,3-Triazolium Ionic Liquids

Michael Graetzel, Paul Joseph Dyson, Shaik Mohammed Zakeeruddin, Hoi Nok Tsao, Pui Shan Genevieve Lau

We describe the design and synthesis of novel low viscosity bicyclic 1,2,3-triazolium ionic liquids. These new salts are applied as nonvolatile electrolytes in dye-sensitized solar cells, affording efficiencies up to 7.07% at low light intensities, and 6.0 ...

Amer Chemical Soc2014

Influence of Structural Variations in Push-Pull Zinc Porphyrins on Photovoltaic Performance of Dye-Sensitized Solar Cells

Michael Graetzel, Shaik Mohammed Zakeeruddin, Chenyi Yi, Fabrizio Giordano, Hoi Nok Tsao

We designed and synthesized two new zinc porphyrin dyes for dye-sensitized solar cells (DSCs). Subtle molecular structural variation in the dyes significantly influenced the performance of the DSC devices. By utilizing these dyes in combination with a coba ...

Wiley-VCH Verlag Berlin2014

Dithieno[2,3-d;2 ',3 '-d ']benzo[1,2-b;4,5-b ']-dithiophene based organic sensitizers for dye-sensitized solar cells

Michael Graetzel, Mohammad Khaja Nazeeruddin, Hoi Nok Tsao, Peng Gao, Xin Guo

We report two novel D-pi-A type organic dyes with a coplanar dithieno[2,3-d; 2',3'-d']benzo[1,2 b;4,5-b']dithiophene (DTBDT) as pi-spacer for dye-sensitized solar cells. A best device performance with a power conversion efficiency of 6.32% is achieved, mak ...

RSC Publishing2014