Heterointerface control of organic semiconductor devices

有机电子材料被广泛用于LED、晶体管和太阳能电池，尽管不太先进。有机半导体器件通常分为两类：通过所谓的“小分子”真空沉积制成的器件和通过成膜材料（通常为聚合物）的溶液加工制成的器件。英国社区，在剑桥的一些早期工作后，往往集中在后一类材料。这样做的理由是双重的。首先，就转化为大规模制造而言，活性半导体的直接低温溶液处理对于低成本处理是非常有吸引力的，特别是在可以通过直接印刷进行图案化的情况下（已经开发了喷墨印刷，例如，用于在全色显示器中沉积红色、绿色和蓝色发光材料）。其次，溶液处理为形成有用的器件结构提出了挑战和机遇。在某些方面，这是笨拙的-通常难以组装多层有机半导体以制造常规的层状异质结构，因为溶剂通常不具有足够的特异性以允许连续的层沉积而不干扰下层-但在其他方面，存在真实的机会来产生将非常难以常规地制造的架构。例如，光伏器件需要电子接受聚合物和空穴接受聚合物的互穿网络，使得在整个半导体层的厚度上吸收的光可以在足够靠近异质结区域的地方产生激子，以产生分离的电荷。在过去10年中取得的快速进展已经将该领域带到了一个水平，其中设备性能已经支撑了一个新兴的行业。对有机异质界面的电子结构的基本理解既支撑了这个行业，也为我们提供了一个新的发现领域，我们需要实现对分子和纳米结构的新水平控制。LED、PV和FET的当前器件性能的局限性由我们在异质界面处控制和测量结构的能力的局限性决定。本项目的愿景是在有机异质界面的分子和纳米尺度结构控制方面实现飞跃式的改进，从而带来有源半导体器件（包括LED、FET和光致发光器件）的电子功能和性能的飞跃式变化。这一丰富的新科学领域的挖掘将为科学和工程带来改变游戏规则的发现。该计划包括各种不同的界面，有机-有机和有机-无机半导体之间;有机半导体和半导体;和有机半导体电极界面。

Organic electronic materials are widely used in LEDs, transistors and, though less advanced, in solar cells. Organic semiconductor devices are generally divided into two classes: those made by vacuum deposition of so-called 'small molecules' and those made by solution-processing of film-forming materials (typically polymers). The UK community, following some of the early work at Cambridge has tended to concentrate on the latter class of materials. The rationale for this is two-fold. Firstly, in terms of translation to large-scale manufacture, direct low-temperature solution processing of active semiconductors is very attractive for low-cost processing, particularly where patterning can be carried out by direct printing (ink-jet printing has been developed, for example, for deposition of red-, green- and blue-emitting materials in full colour displays). Secondly, solution processing presents challenges and opportunities for the formation of useful device structures. In some respects it is awkward - it is generally difficult to assemble multiple layers of organic semiconductor to make conventional laminar heterostructures because solvents are typically not sufficiently specific to allow successive layer depositions without disturbing lower layers - but in other respects, there are real opportunities to generate architectures that would be very difficult to make conventionally. For example, interpenetrating networks of electron-accepting and hole-accepting polymers are required for photovoltaic devices, so that light absorbed throughout the thickness of the semiconductor layer can generated excitons close enough to a region of heterojunction to generate separated charges. The rapid progress made over the last 10 years has taken the field to a level where device performance already sustains a fledgling industry. Basic understanding of the electronic structure of organic heterointerfaces both underpins this industry, and also presents us with a new landscape for discovery where we need to achieve a new level of control over molecular and nanoscale structure. Limitations in current device performance, for LEDs, PVs and FETs, are determined by limitations in our ability to control and measure structures at heterointerfaces. The vision of the present project is to achieve a step-change improvement in the control of molecular and nanoscale structure at organic heterointerfaces and thus to bring about a step-change in electronic functionality and performance of active semiconductor devices including LEDs, FETs and photovoltaics .The mining of this rich new seam of science will deliver game-changing discoveries for both science and engineering. The programme encompasses a variety of different interfaces, between organic-organic and organic-inorganic semiconductors; organic semiconductors and dielectrics; and organic semiconductor-electrode interfaces.