A new series of stable, unsymmetrical squaraine near-IR sensitizers (JK-216 and JK-217), which are assembled using both thiophenyl pyrrolyl and indolium groups, exhibit a panchromatic light harvesting up to 780 nm. The JK-216 based cell exhibited a record efficiency of 6.29% for near-IR DSSCs. In addition, the JK-217 device showed an excellent stability under a light soaking test at 60 °C for 1000 h.

A new type of organic sensitizers incorporating a planar amine unit have been synthesized and demonstrated to be a highly efficient sensitizers, showing evidence of lateral interactions on the TiO(2) surface. Under standard global air mass 1.5 solar conditions, the JK-98 sensitized cell gave a short circuit photocurrent density (J(sc)) of 16.78 mA cm(-2), an open-circuit voltage (V(oc)) of 0.745 V, and a fill factor (ff) of 0.70, corresponding to an overall conversion efficiency (η) of 8.71%.

Annulated thiophene perylene bisimides and their triphenyl-amine based oligomers have been synthesized. One of the oligomers FPTTPA has been demonstrated to be an efficient electron donor in bulk heterojunction (BHJ) organic solar cells, giving a power conversion efficiency of 1.42%.

A facile new protocol for the synthesis of iodinated derivatives of fluorinated benzothiadiazoles is demonstrated for the production of p-type semiconducting materials. The newly synthesized small-molecule compounds bis[TPA-diTh]-MonoF-BT and bis[TPA-diTh]-DiF-BT exhibited a power conversion efficiency of 2.95% and a high open-circuit voltage of 0.85 V in solution-processed small-molecule organic solar cells.

High-performance organic semiconductors based on an electron-rich alkylsilylethynyl benzodithiophene (TIPSBDT) core were newly synthesized and characterized for use in solution-processed small-molecule organic solar cells. The rigid and extended π-conjugation of the TIPSBDT motifs facilitates intramolecular charge transfer and intermolecular π–π packing interactions of semiconducting small molecules in the BHJ film enhanced by processing additives and induces deep HOMO levels producing high open-circuit voltage of ∼1.0 V, exhibiting notable power conversion efficiency of 5.84% from a bulk-heterojunction film with PC61BM.

Well-organized (CH3NH3)PbI3 perovskite films fabricated from various solution-processing conditions were characterized and used in hybrid solar cells with PC71BM planar heterojuncion films, exhibiting a high power-conversion efficiency of 12.2% with the better photocurrent and fill factor compared to those with PC61BM due to a better spectral response in the visible region and a better planar junction with the Ag electrode than the PC61BM.

The synthesis and photovoltaic characteristics of new organic semiconductors, [bisDMFA-Th]-BT-HxTh 3 (1), [bisDMFA-Th]-MonoF-BT-HxTh 3 (2), and [bisDMFATh]-DiF-BT-HxTh 3 (3), are reported. These semiconductors have an unsymmetrical donor A−acceptor−donor B (D A -A-D B ) framework composed of a benzothiadiazole (BT;fluorinated or unfluorinated) acceptor between two different donors, bisDMFA and terthiophene. We have demonstrated that these compounds are suitable for use in p-type organic semiconductors for high efficiency solution-processed small molecule organic solar cells (SMOSCs), for which we achieved a remarkable power conversion efficiency of 4.24% with a maximum V oc of 0.89 V. The fluorine substitution on BT decreased its HOMO level and increased hole mobilities of [bisDMFA-Th]-BT-HxTh 3 derivatives, leading to an increased V oc in the SMOSCs and improved hole carrier transport properties of the material. In addition, we determined that the insertion of a TiO x functional layer into a bulk heterojunction (BHJ) solar cell significantly reduced the interfacial resistance between the photoactive film and metal electrode, resulting in an increased photocurrent with facile electron transfer between these two layers.

We have synthesized and characterized four organic dyes (H1-H4) based on a 3,6-disubstituted carbazole donor as sensitizers in dye-sensitized solar cells. These dyes have high molar extinction coefficients and energy levels suitable for electron transfer from an electrolyte to nanocrystalline TiO(2) particles. Under standard air mass 1.5 global (AM 1.5 G) solar irradiation, a device using dye H4 exhibits a short-circuit current density (J(sc)) of 13.7 mA cm(-2), an open-circuit voltage (V(oc)) of 0.68 V, a fill factor (FF) of 0.70, and a calculated efficiency of 6.52%. This performance is comparable to that of a reference cell based on N719 (7.30%) under the same conditions. After 1000 hours of visible-light soaking at 60 °C, the overall efficiency remained at 95% of the initial value.