Papers
Topics
Authors
Recent
Search
2000 character limit reached

Wide band gap chalcogenide semiconductors

Published 17 Oct 2019 in cond-mat.mtrl-sci | (1910.08153v3)

Abstract: Wide band gap semiconductors are essential for today's electronic devices and energy applications due to their high optical transparency, as well as controllable carrier concentration and electrical conductivity. There are many categories of materials that can be defined as wide band gap semiconductors. The most intensively investigated are transparent conductive oxides (TCOs) such as ITO and IGZO used in displays, carbides and nitrides used in power electronics, as well as emerging halides (e.g. CuI) and 2D electronic materials used in various optoelectronic devices. Chalcogen-based (S, Se, Te) wide band gap semiconductors are less heavily investigated but stand out due to their propensity for p-type doping, high mobilities, high valence band positions (i.e. low ionization potentials), and broad applications in electronic devices such as CdTe solar cells. This manuscript provides a review of wide band gap chalcogenide semiconductors. First, we outline general materials design parameters of high performing transparent conductors. We proceed to summarize progress in wide band gap (Eg > 2 eV) chalcogenide materials, such as II-VI MCh binaries, CuMCh2 chalcopyrites, Cu3MCh4 sulvanites, mixed anion layered CuMCh(O,F), and 2D materials, among others, and discuss computational predictions of potential new candidates in this family, highlighting their optical and electrical properties. We finally review applications of chalcogenide wide band gap semiconductors, e.g. photovoltaic and photoelectrochemical solar cells, transparent transistors, and diodes, that employ wide band gap chalcogenides as either an active or passive layer. By examining, categorizing, and discussing prospective directions in wide band gap chalcogenides, this review aims to inspire continued research on this emerging class of transparent conductors and to enable future innovations for optoelectronic devices.

Citations (274)

Summary

  • The paper offers a detailed survey of wide band gap chalcogenide semiconductors, outlining experimental and computational frameworks that assess their optoelectronic potential.
  • It reviews material families such as binary II-VI compounds, ternary chalcopyrites, and quaternary chalcogenides, linking band gap properties to device performance.
  • The study advocates advanced computational screening and novel synthesis techniques to improve stability and doping, paving the way for next-generation optoelectronic devices.

Review of Wide Band Gap Chalcogenide Semiconductors

The reviewed paper meticulously surveys the field of wide band gap (WBG) chalcogenide semiconductors, emphasizing their potential for optoelectronic applications in comparison to the more extensively researched oxides. This detailed assessment encapsulates both experimental and theoretical investigations, making a compelling case for further research into this underexplored material class.

Within the context of wide band gap semiconductor materials, chalcogenides offer a distinct set of properties. These materials, composed of Group VI chalcogens (S, Se, Te), show a high affinity for p-type doping, high mobilities, and favorable valence band positions, making them suitable candidates for applications in electronic devices, including photovoltaic cells, diodes, and transparent transistors.

Material Design Parameters and Research Methods

The paper delineates critical parameters that govern the optoelectronic properties of WBG chalcogenides. These key criteria include synthesizability and stability, wide band gap sufficient for transparency, high mobility, and the capability for n- or p-doping. This forms a comprehensive framework for assessing these materials based on both computational predictions and experimental validation.

The authors further discuss recent advancements in computational methodologies, specifically high-throughput screenings facilitated by platforms such as the Materials Project. These frameworks enable efficient filtering for potential new semiconductor materials, considering thermodynamic stability and promising band gap properties.

Materials Classification and Properties

The paper classifies the WBG chalcogenide semiconductors into several families, including binary II-VI compounds, ternary chalcopyrites, and quaternary mixed-anion chalcogenides. The II-VI class, featuring materials like ZnS and MgCh, demonstrates significant potential due to their robust band gaps and the ability to form favorable heterostructures.

Among ternary compounds, chalcopyrite structures such as CuAlSâ‚‚ and CuGaSâ‚‚ receive particular attention for their promising gap values and potential ambipolar conduction. The paper extensively catalogs these materials, offering a summary of their experimentally measured band gaps and conductivities.

Quaternary chalcogenides, like the layered CuInSe2 and its alloys, are highlighted for their photovoltaic applications. The review provides insights into their attractive properties, including reduced recombination losses due to high VBM positions and conducive defect tolerances.

Applications and Future Directions

Wide band gap chalcogenides have already found practical applications in various optoelectronic devices. In photovoltaic technology, CdTe and CIGS cells utilize WBG chalcogenides for improved efficiency through better band alignment and spectral response. Notably, applications in tandem solar cells, LEDs, and transparent electronics further elucidate the versatility of these materials.

Moving forward, the paper underscores several pathways for advancement in this domain. This includes expanding the database of computationally predicted materials to discover more candidate high-mobility p-type conductors and exploring mixed-anion strategies to fine-tune optoelectronic properties. The synthesis of novel compounds and smart material engineering to enhance stability and interfacial properties are deemed necessary steps towards integrating chalcogenides in a broader range of applications.

In conclusion, the comprehensive review presented in the paper establishes a solid groundwork for continued research in the wide band gap chalcogenide semiconductor field. The emphasis lies in their unique properties that set them apart from traditional oxides, positioning them as promising candidates for next-generation optoelectronic devices. This review advocates for a concerted effort among materials scientists to unlock the full potential of these semiconductors, enlarging the spectrum of possibilities in energy conversion and transparent electronic applications.

Paper to Video (Beta)

No one has generated a video about this paper yet.

Whiteboard

No one has generated a whiteboard explanation for this paper yet.

Open Problems

We haven't generated a list of open problems mentioned in this paper yet.

Continue Learning

We haven't generated follow-up questions for this paper yet.

Collections

Sign up for free to add this paper to one or more collections.