Diversification of Device Platforms by Molecular Layers: Hybrid Sensing Platforms, Monolayer Doping, and Modeling

Abstract

Inorganic materials such as semiconductors, oxides, and metals are ubiquitous in a wide range of device technologies owing to the outstanding robustness and mature processing technologies available for such materials. However, while the important contribution of inorganic materials to the advancement of device technologies has been well established for decades, organic−inorganic hybrid device systems, which merge molecular functionalities with inorganic platforms, represent a newer domain that is rapidly evolving at an increasing pace. Such devices benefit from the great versatility and flexibility of the organic building blocks merged with the robustness of the inorganic platforms. Given the overwhelming wealth of literature covering various approaches for modifying and using inorganic devices, this feature article selectively highlights some of the advances made in the context of the diversification of devices by surface chemistry. Particular attention is given to oxide−semiconductor systems and metallic surfaces modified with organic monolayers. The inorganic device components, such as semiconductors, metals, and oxides, are modified by organic monolayers, which may serve as either active, static, or sacrificial components. We portray research directions within the broader field of organic−inorganic hybrid device systems that can be viewed as specific examples of the potential of such hybrid device systems given their comprehensive capabilities of design and diversification. Monolayer doping techniques where sacrificial organic monolayers are introduced into semiconducting elements are reviewed as a specific case, together with associated requirements for nanosystems, devices, and sensors for controlling doping levels and doping profiles on the nanometric scale. Another series of examples of the flexibility provided by the marriage of organic functional monolayers and inorganic device components are represented by a new class of biosensors, where the organic layer functionality is exploited in a functioning device for sensing. Considerations for relying on oxide-terminated semiconductors rather than the pristine semiconductor material as a platform both for processing and sensing are discussed. Finally, we cover aspects related to the use of various theoretical and computational approaches to model organic−inorganic systems. The main objectives of the topics covered here are (i) to present the advances made in each respective domain and (ii) to provide a comprehensive view of the potential uses of organic monolayers and self-assembly processes in the rapidly evolving field of molecular−inorganic hybrid device platforms and processing methodologies. The directions highlighted here provide a perspective on a future, not yet fully realized, integrated approach where organic monolayers are combined with inorganic platforms in order to obtain versatile, robust, and flexible systems with enhanced capabilities.

Boron Monolayer Doping: Role of Oxide Capping Layer, Molecular Fragmentation, and Doping Uniformity at the Nanoscale

“…Thorough discussion of monolayer doping methodologies and state of the art in the field can be found elsewhere. [ 35 ] Briefly, the key difference between MLD and the other two techniques discussed here is the deposition of SiO 2 capping layer on the dopant containing monolayer for MLD, while no capping is applied for MLCD and R‐MLD. Instead, a target substrate is placed on top of the donor substrate in direct contact for MLCD.…”

Emergence of Supramolecular Order from Combined Linear Amphiphilic and Diphosphonate Molecules

“…Molecules with linear chains exhibit remarkable self-assembly properties, with applications ranging from liquid crystal devices to insulating monolayers in organic devices, − coatings, − optical components, , among others. Recently, they have been used to induce doping of inorganic layers through a technique called monolayer doping (MLD) that allows for the development of high-quality shallow junctions in semiconductor devices. − Generally, these systems are employed to achieve long-range order in their pure form, i.e., a single compound that exhibits structurally perfect positional registry under simple deposition methods such as spin coating or drop coating . Such ability to produce a self-assembled registry is of economic interest since scale-up fabrication processes can be easily envisaged.…”

Direct Assembly and Metal-Ion Binding Properties of Oxytocin Monolayer on Gold Surfaces

“…1−4 Using peptides as biosensors for metal ions 5−7 or as smart nanomaterials for filtration 8 and purification applications is an emerging and promising approach. 9 These applications require the attachment of the peptides to surfaces. 10,11 Anchoring peptides to surfaces in a way that the inherent metal binding properties are maintained is a synthetic challenge since, in many cases, this process requires chemical modifications of the peptide.…”

“…Many peptides are natural binders of metal ions with distinct selectivity and specificity. − Using peptides as biosensors for metal ions − or as smart nanomaterials for filtration and purification applications is an emerging and promising approach . These applications require the attachment of the peptides to surfaces. , Anchoring peptides to surfaces in a way that the inherent metal binding properties are maintained is a synthetic challenge since, in many cases, this process requires chemical modifications of the peptide. , Developing streamlined processes that will allow for the attachment of native peptides to surfaces without abolishing their metal binding properties is a valuable addition to the field.…”