The Interlayer Method: A Universal Tool for Energy Level Alignment Tuning at Inorganic/Organic Semiconductor Heterojunctions

Abstract

The combination of inorganic and organic semiconductors in a heterojunction is considered a promising approach to overcome limitations of each individual material class. However, to date only few examples of improved (opto‐)electronic functionality have been realized with such hybrid heterojunctions. The key to unraveling the full potential offered by inorganic/organic semiconductor heterojunctions is the ability to deliberately control the interfacial electronic energy levels. Here, a universal approach to adjust the offset between the energy levels at inorganic/organic semiconductor interfaces is demonstrated: the interlayer method. A monolayer‐thick interlayer comprising strong electron donor or acceptor molecules is inserted between the two semiconductors and alters the energy level alignment due to charge transfer with the inorganic semiconductor. The general applicability of this method by tuning the energy levels of hydrogenated silicon relative to those of vacuum‐processed films of a molecular semiconductor as well as solution‐processed films of a polymer semiconductor is exemplified, and is shown that the energy level offset can be changed by up to 1.8 eV. This approach can be used to adjust the energy levels at the junction of a desired material pair at will, and thus paves the way for novel functionalities of optoelectronic devices.

Effects of a Flexible Ion Gel as an Active Outer-Layer when in Contact with a Metallic Electrode

“…Different electrical properties could provide higher or lower charge carrier density flowing throughout the device as, e.g, charge carrier mobility from the semiconductor or energy alignment at the interfaces. This second example can be improved by playing with the energy level matching at the interface of two different materials that can be semiconductor/semiconductor (S/S) or metal/semiconductor (M/S) interfaces [8][9][10][11] .…”

“…The addition of an interlayer between M/S interfaces is a common technique to improve charge carriers injection 8,9,12 .…”

Controllable Synthesis and Effects of Porphyrin Copper Nanostructures on Photoelectric Properties

“…Thus, the development of active materials that have an excellent photoelectric effect is a very significant topic. Currently, our research on photoelectric materials is mainly focused on the inorganic semiconductor materials, , which are often limited in application due to inefficient light absorption, and so forth. Organic semiconductors have gradually become a research point of special interest and have increasingly fascinated researchers due to their fast light response, low cost, easy processing, and so forth. , In addition, organic materials possess diverse structural compositions and properties, which allow us to design their molecular structure for achieving the desired performance and significantly promote their wide application in the photoelectric field. − Porphyrins are an important class of molecular semiconductors that have been designed into a variety of functional materials for photoelectric conversion, conductive sensing, photolysis of water, , and catalysis , owing to their unique electronic structure and optoelectronic properties.…”

“…Thus, the development of active materials that have an excellent photoelectric effect is a very significant topic. Currently, our research on photoelectric materials is mainly focused on the inorganic semiconductor materials, 7,8 which are often limited in application due to inefficient light absorption, and so forth. Organic semiconductors have gradually become a research point of special interest and have increasingly fascinated researchers due to their fast light response, low cost, easy processing, and so forth.…”

Engineering of Printable and Air‐Stable Silver Electrodes with High Work Function using Contact Primer Layer: From Organometallic Interphases to Sharp Interfaces

“…A promising approach to meet this requirement is the use of strong molecular acceptors such as the recently synthesized 2,3,5,6-tetrafluoro-7,7,8,8-tetracyano-quinodimethane (F 4 TCNQ) and 1,3,4,5,7,8-hexafluorotetra-cyanonaphthoquinodimethane (F 6 TCNNQ), that are often used as p-dopants in OSC films, also for the preparation of contact primer layers. [18] Previous studies have shown, that for such adlayers adsorbed on metal surfaces the push-back effect is compensated by a notable charge transfer…”