33-1: Invited Paper: Exploring the Formation and Growth of Organic Semiconductors with mm-Scale Grains
33-1: Invited Paper: Exploring the Formation and Growth of Organic Semiconductors with mm-Scale Grains
复制标题
33-1：特邀论文：探索毫米级颗粒有机半导体的形成和生长
DOI：
10.1002/sdtp.12587
复制
发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Dull, Jordan T.
中科院分区：
文献类型：
--
作者：
Rand, Barry P.;Fusella, Michael A.;Shayegan, Komron;Dull, Jordan T.
虽然单晶形式的有机半导体的迁移率已达到创纪录的水平，但这种晶体的块状性质阻碍了它们在器件中的实际应用。在这里，我们讨论了我们为实现晶粒尺寸达 1 毫米的有机半导体无针孔薄膜所做的努力。其中一种材料是红荧烯，但我们还将展示我们在适用于有机发光二极管的其他材料方面的努力，例如电子传输层2,2',2"-(1,3,5-苯并三基)-三(1-苯基-1-H-苯并咪唑)(TPBi)。对于红荧烯，我们将展示我们在理解晶体形成、外延和晶体管方面所做的努力。同质外延研究发现了这些薄膜中点和线缺陷形成的证据，表明同质外延并未处于平衡或无应变状态。作为螺位错解决的点缺陷可以在接近平衡的条件下消除，但我们无法消除线缺陷的形成。然而，我们能够通过在红荧烯块状单晶上生长来消除这些线缺陷，这表明线缺陷是薄膜模板中内置的应变结果，表明通常有机晶体薄膜可能不会采用块状晶体的精确晶格。由这些大颗粒红荧烯薄膜制成的晶体管显示出高达 3.5 cm2V−1s−1 的载流子迁移率，非常接近单晶值，凸显了它们的实际应用潜力。
While record mobilities have been reported for organic semiconductors in their single crystal form, the bulk nature of such crystals prohibit their practical application in devices. Here, we discuss our efforts to realize pinhole free films of organic semiconductors with grains of up to 1 mm in extent. One such material is rubrene, but we will also show our efforts on other materials applicable to organic light emitting diodes, such as the electron transport layer 2,2′,2″‐(1,3,5‐benzinetriyl)‐tris(1‐phenyl‐1‐H‐benzimidazole) (TPBi). For rubrene, we will show our efforts to understand crystal formation, epitaxy, and transistors. Homoepitaxial studies uncover evidence of point and line defect formation in these films, indicating that homoepitaxy is not at equilibrium or strain‐free. Point defects that are resolved as screw dislocations can be eliminated under closer‐to‐equilibrium conditions, whereas we are not able to eliminate the formation of line defects. We are, however, able to eliminate these line defects by growing on a bulk single crystal of rubrene, indicating that the line defects are a result strain built into the thin film template, indicating that, in general, organic crystalline thin films may not adopt the exact lattice of a bulk crystal. Transistors made out of these large‐grained films of rubrene display charge carrier mobility of up to 3.5 cm2V−1s−1, very close to single crystal values, highlighting their potential for practical application.