Precise Control of Phase Separation Enables 12% Efficiency in All Small Molecule Solar Cells

Compared to conjugated polymers, small‐molecule organic semiconductors present negligible batch‐to‐batch variations, but presently provide comparatively low power conversion efficiencies (PCEs) in small‐molecular organic solar cells (SM‐OSCs), mainly due to suboptimal nanomorphology. Achieving precise control of the nanomorphology remains challenging. Here, two new small‐molecular donors H13 and H14 , created by fluorine and chlorine substitution of the original donor molecule H11 , are presented that exhibit a similar or higher degree of crystallinity/aggregation and improved open‐circuit voltage with IDIC‐4F as acceptor. Due to kinetic and thermodynamic reasons, H13 ‐based blend films possess relatively unfavorable molecular packing and morphology. In contrast, annealed H14 ‐based blends exhibit favorable characteristics, i.e., the highest degree of aggregation with the smallest paracrystalline π–π distortions and a nanomorphology with relatively pure domains, all of which enable generating and collecting charges more efficiently. As a result, blends with H13 give a similar PCE (10.3%) as those made with H11 (10.4%), while annealed H14 ‐based SM‐OSCs have a significantly higher PCE (12.1%). Presently this represents the highest efficiency for SM‐OSCs using IDIC‐4F as acceptor. The results demonstrate that precise control of phase separation can be achieved by fine‐tuning the molecular structure and film formation conditions, improving PCE and providing guidance for morphology design.     

Comparison of testosterone and insulin-like peptide 3 secretions in response to human chorionic gonadotropin in cultured interstitial cells from scrotal and retained testes in dogs

Levels of testosterone and insulin-like peptide 3 (INSL3) secretions in response to different doses of human chorionic gonadotropin (hCG) in cultured interstitial cells were compared between retained and scrotal testes in dogs. Retained (n=10) and scrotal (n=9) testes were obtained from small-breed dogs. The testicular tissues were dispersed in Dulbecco's Modified Eagle Medium with Ham's nutrient mixture containing 2000 PU/ml dispase II and 10% fetal bovine serum. The cells were plated with differing concentrations (0-10 IU/ml) of hCG for 18 h in multiwell-plates. Testosterone and INSL3 in the same spent medium were measured by enzyme-immunoassays (EIA). A new EIA with a reliable detection range of 0.025-5 ng/ml was developed in order to measure canine INSL3 in culture medium. Dose-dependent stimulation of testosterone by hCG was observed in the cells of both retained and scrotal testes. The incremental rate of testosterone secretion was significantly lower at 0.1, 1 and 10 IU/ml hCG in the cells of retained testes than in scrotal testes, however. INSL3 secretion was significantly stimulated at 10 IU/ml hCG relative to unstimulated controls comprising cells of scrotal testes; no such stimulation was observed in the cells of retained testes. At 10 IU/ml hCG, the incremental rate of INSL3 was significantly lower in the cells of retained testes than scrotal testes. These results suggest that LH-induced secretory testosterone and INSL3 responses are lower in the interstitial cells of retained testes than of scrotal testes. Furthermore, the high concentrations of LH may acutely stimulate INSL3 release in scrotal testes of dogs, but not in retained testes.     

Insulin-like peptide 3 stimulates testosterone secretion in mouse Leydig cells via cAMP pathway

Testicular Leydig cells secrete insulin-like peptide 3 (INSL3) and express its receptor, RXFP2. However, the effects of INSL3 on endocrine function of Leydig cells are unknown. The present study examines the effects of INSL3 on mouse Leydig cells taking testosterone and cAMP secretions as endpoints. Leydig cells were isolated from testicular interstitial cells obtained from 8-week-old male mice. Cells were then plated in the presence or absence of mouse, human, canine or bovine INSL3 (0-100ng/ml) for 18h in multiwell-plates (96 wells) in different cell densities (2500, 5000, 10,000 or 20,000 cells per well). The effects of bovine INSL3 (100ng/ml) on testosterone secretion by Leydig cells were examined in the presence or absence of, an adenylate cyclase inhibitor, SQ 22536 (1μM) or INSL3 antagonist (bovine and human; 100ng/ml). Testosterone and cAMP in spent medium were measured by enzyme immunoassay. All INSL3 species tested significantly stimulated the testosterone secretion in Leydig cells, and the maximum stimulation was observed with 100ng/ml bovine INSL3 at the lowest Leydig cell density (2500 cells per well). Moreover, bovine INSL3 (100ng/ml) significantly stimulated the cAMP production from Leydig cells maximally at 1h, and remained significantly elevated even at 18h. SQ 22536 and INSL3 antagonists (bovine and human) significantly reduced INSL3-stimulated testosterone secretion from Leydig cells. Taken together, stimulatory effects of INSL3 on testosterone secretion in Leydig cells are exerted via the activation of cAMP, suggesting a new autocrine function of INSL3 in males.     

Improvement of Photovoltaic Performance of Polymer Solar Cells by Rational Molecular Optimization of Organic Molecule Acceptors

Two n‐type organic semiconductor (n‐OS) small molecules m‐ITIC‐2F and m‐ITIC‐4F with fluorinated 2‐(2,3‐dihydro‐3‐oxo‐1H‐inden‐1‐ylidene)propanedinitrile (IC) terminal moieties are prepared, for the application as an acceptor in polymer solar cells (PSCs), to further improve the photovoltaic performance of the n‐OS acceptor 3,9‐bis(2‐methylene‐(3‐(1,1‐dicyanomethylene) indanone) ‐5,5,11,11‐tetrakis(3‐hexylphenyl)‐dithieno[2,3‐d:2′,3′‐d′]‐sindaceno[1,2‐b:5,6‐b′]‐dithiophene (m‐ITIC). Compared to m‐ITIC, these two new acceptors show redshifted absorption, higher molecular packing order, and improved electron mobilities. The power conversion efficiencies (PCE) of the as‐cast PSCs with m‐ITIC‐2F or m‐ITIC‐4F as an acceptor and a low‐cost donor–acceptor (D–A) copolymer PTQ10 as a donor reach 11.57% and 11.64%, respectively, which are among the highest efficiency for the as‐cast PSCs so far. Furthermore, after thermal annealing treatment, improved molecular packing and enhanced phase separation are observed, and the higher PCE of 12.53% is achieved for both PSCs based on the two acceptors. The respective and unique advantage with the intrinsic high degree of order, molecular packing, and electron mobilities of these two acceptors will be suitable to match with different p‐type organic semiconductor donors for higher PCE values, which provide a great potential for the PSCs commercialization in the near future. These results indicate that rational molecular structure optimization is of great importance to further improve photovoltaic properties of the photovoltaic materials.