A series of new-type of donor-p-acceptor dyes (TCT-1-6) utilizing 1,3,5-triazine as p spacers wer... more A series of new-type of donor-p-acceptor dyes (TCT-1-6) utilizing 1,3,5-triazine as p spacers were synthesized. These dyes were characterized by 1 H NMR, ESI-MS, EA, and X-ray crystallography. Their photovoltaic performances were also investigated. An overall photon-to-electron conversion efficiency of 1.8% was achieved with the DSSC based on the dye TCT-1(J sc = 3.33 mA/cm 2 , V oc = 757 mV, FF = 71.8%) under AM 1.5G illumination (100 mW/cm 2 ).
A new series of triazine-containing donorep-acceptor organic sensitizers (TCT-(7e19)) with broad ... more A new series of triazine-containing donorep-acceptor organic sensitizers (TCT-(7e19)) with broad absorptions and high molar extinction coefficients have been designed and synthesized based on our previous work. All these dyes were completely characterized by 1 H NMR, ESI-MS, EA, IR, UVevis, and cyclic voltammetry. The photovoltaic performances of dye-sensitized solar cells (DSSCs) based on these dyes were investigated. The effect of conjugating length and terminating groups on the absorption properties and photovoltaic performances were discussed. An overall photon-to-electron conversion efficiency of 3.69% was achieved with the DSSC based on the dye TCT-13 (J sc ¼7.76 mA cm À2 , V oc ¼691 mV, FF¼68.8%) under AM 1.5G illumination (100 mW/cm 2 ).
Two novel efficient blue emitters (TTT-1, TTT-2) containing 1,3,5-triazine, thiophene and triphen... more Two novel efficient blue emitters (TTT-1, TTT-2) containing 1,3,5-triazine, thiophene and triphenylamine have been designed and synthesized. Organic light emitting diodes (OLEDs) using these new triazine derivatives as emissive layers, ITO/TAPC (60 nm)/TTT-1 (Device A) or TTT-2 (Device B) (40 nm)/TPBi (60 nm)/LiF (1 nm)/Al (100 nm), were fabricated and tested. The OLEDs exhibited good performances with low turn-on voltage of 3 V, maximum luminance of ca. 8990 cd/m 2 for TTT-1 and 15,980 cd/m 2 for TTT-2, and maximum luminance efficiency of 4.7 cd/A for TTT-1 and 4.0 cd/A for TTT-2, respectively.
"One way to improve the spectral response of solar cells in the ultraviolet (UV) region is to con... more "One way to improve the spectral response of solar cells in the ultraviolet (UV) region is to convert high energy photons into
lower energy ones via luminescent down-shifting (LDS) technique. Eu3+ complexes are excellent LDS species because of
their high luminescence quantum efficiency and large Stokes-shift. In this paper, we aim to optimize the LDS property of
Eu3+ complexes for monocrystalline silicon (c-Si) photovoltaic (PV) modules by chemical modification of the UV
absorbing antenna ligands. Our results show that the LDS performances of Eu3+ complexes are strongly dependent on their
absorption and emission properties. By carefully modifying the absorption and emission features, the LDS performances of
Eu3+ complexes can be significantly improved. The spectroscopic features of the Eu3+ complex with a bispinene-containing
bipyridyl ligand match well with the requirement of ideal LDS species for the c-Si PV module. Simple coating of polyvinyl
acetate film doped with this complex onto the surface of c-Si PV module leads to increase of the external quantum
efficiency in the UV region and enhancement of the PV module efficiency (from 16.05% to 16.37%)."
Transition-metal-catalyzed aryl-aryl coupling though C-H bonds activation, termed direct arylatio... more Transition-metal-catalyzed aryl-aryl coupling though C-H bonds activation, termed direct arylation, has been widely used in
synthesis of a broad range of small molecules. In contrast to traditional coupling methods such as Suzuki coupling and Stille coupling, direct
arylation does not involve tedious preparation of unstable, toxic organometallic reagents. Despite these advantages, direct arylation
has not been applied to synthesis of -conjugated polymers until recently. In this perspective, we summarize the progress of direct arylation
polymerization for synthesis of various -conjugated polymers, including homopolymers of polythiophene derivatives and donoracceptor
alternating copolymers. We also discuss present challenges and future directions of this nascent methodology of polymerization
for synthesis of functional -conjugated polymers that can find applications in optoelectronic devices such as solar cells and field effect
transistors.
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Papers by Kai Wang
lower energy ones via luminescent down-shifting (LDS) technique. Eu3+ complexes are excellent LDS species because of
their high luminescence quantum efficiency and large Stokes-shift. In this paper, we aim to optimize the LDS property of
Eu3+ complexes for monocrystalline silicon (c-Si) photovoltaic (PV) modules by chemical modification of the UV
absorbing antenna ligands. Our results show that the LDS performances of Eu3+ complexes are strongly dependent on their
absorption and emission properties. By carefully modifying the absorption and emission features, the LDS performances of
Eu3+ complexes can be significantly improved. The spectroscopic features of the Eu3+ complex with a bispinene-containing
bipyridyl ligand match well with the requirement of ideal LDS species for the c-Si PV module. Simple coating of polyvinyl
acetate film doped with this complex onto the surface of c-Si PV module leads to increase of the external quantum
efficiency in the UV region and enhancement of the PV module efficiency (from 16.05% to 16.37%)."
synthesis of a broad range of small molecules. In contrast to traditional coupling methods such as Suzuki coupling and Stille coupling, direct
arylation does not involve tedious preparation of unstable, toxic organometallic reagents. Despite these advantages, direct arylation
has not been applied to synthesis of -conjugated polymers until recently. In this perspective, we summarize the progress of direct arylation
polymerization for synthesis of various -conjugated polymers, including homopolymers of polythiophene derivatives and donoracceptor
alternating copolymers. We also discuss present challenges and future directions of this nascent methodology of polymerization
for synthesis of functional -conjugated polymers that can find applications in optoelectronic devices such as solar cells and field effect
transistors.