Surface and interface of epitaxial CdTe film on CdS buffered van der Waals mica substrate

Yang, Yunbo; Seewald, Lucas; Mohanty, Dibyajyoti; Wang, Y.; Zhang, L.H.; Kisslinger, Kim; Xie, Weiyu; Shi, Jian; Bhat, Ishwara B.; Zhang, Shou-Cheng; Lu, Toh‐Ming; Wang, G.-C.

doi:10.1016/j.apsusc.2017.03.260

Cited by 18 publications

(14 citation statements)

References 76 publications

(103 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A significant improvement in crystallinity was evidenced by the XRD rocking curve measurement (Figure B). An extremely low FWHM value of ≈0.05° was achieved, which is ≈1/15 of the 0.73° of the 1.5–2 µm thick CdTe grown on graphene‐buffered Si substrate and ≈1/52 of the 2.6° of the 2 µm thick CdTe film grown on CdS‐buffered mica . Figure C displays the (mica [100]; mica [001]) reciprocal space mapping (RSM) of the vdWE CdTe/mica around the asymmetric mica (0‐48) peak.…”

Section: Comparison Of Vdwe Cdte Photodetectors and Other Photodetecmentioning

confidence: 99%

Ultrahigh‐Detectivity Photodetectors with Van der Waals Epitaxial CdTe Single‐Crystalline Films

Lian

Zhu

Wang

et al. 2019

Small

View full text Add to dashboard Cite

Van der Waals epitaxy (vdWE) is crucial for heteroepitaxy of covalence‐bonded semiconductors on 2D layered materials because it is not subject to strict substrate requirements and the epitaxial materials can be transferred onto various substrates. However, planar film growth in covalence‐bonded semiconductors remains a critical challenge of vdWE because of the extremely low surface energy of 2D materials. In this study, direct growth of wafer‐scale single‐crystalline cadmium telluride (CdTe) films is achieved on 2D layered transparent mica through molecular beam epitaxy. The vdWE CdTe films exhibit a flat surface resulting from the 2D growth regime, and high crystal quality as evidenced by a low full width at half maximum of 0.05° for 120 nm thick films. A perfect lattice fringe appears at the interfaces, implying a fully relaxed state of the epitaxial CdTe films correlated closely to the unique nature of vdWE. Moreover, the vdWE CdTe photodetectors demonstrate not only ultrasensitive optoelectronic response with optimal responsivity of 834 A W−1 and ultrahigh detectivity of 2.4 × 1014 Jones but also excellent mechanical flexibility and durability, indicating great potential in flexible and wearable devices.

show abstract

Section: Comparison Of Vdwe Cdte Photodetectors and Other Photodetecmentioning

confidence: 99%

Ultrahigh‐Detectivity Photodetectors with Van der Waals Epitaxial CdTe Single‐Crystalline Films

Lian

Zhu

Wang

et al. 2019

Small

View full text Add to dashboard Cite

show abstract

“…The fwhm of CdTe (111) rocking curve (Figure 5e) is about 1.4°, which is much smaller that of 2.6°from the epitaxial CdTe film grown on epi-CdS/mica by MOCVD. 13 For the in-plane orientation, there are also six peaks with 60°a part in the azimuthal scan of CdTe (111), as shown in Figure 5f. It is similar to the CdTe grown directly on mica (Figure 1e and Figure S1), with a second set of orientation domain.…”

Section: Methodsmentioning

confidence: 91%

“…Six peaks with 60°azimuthal angular separation between adjacent peaks are found, which is consistent with the hexagonal symmetry of wurtzite CdS crystal structure. 13,25 The average fwhm of these six peaks is about 8.8°. Therefore, it can be concluded that the CdS buffer layer deposited on mica is an epitaxial single-crystalline film.…”

Section: Methodsmentioning

confidence: 98%

“…This small peak is from CdS (0002). 13,24,25 The inset of Figure 5a is a magnified spectrum of the CdS (0002) and mica (006) peaks. The CdS (0002) peak is at about 26.68°.…”

Section: Methodsmentioning

confidence: 99%

“…The average fwhm of these six peaks is about 3.6°, also smaller than that of 10.8°from the epi-CdTe film grown on epi-CdS/mica by MOCVD. 13 Therefore, we obtained epi-CdTe film on epi-CdS/mica substrate through a VTD process, and the quality is better than that grown by MOCVD.…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Epitaxial CdTe Thin Films on Mica by Vapor Transport Deposition for Flexible Solar Cells

Wen

Sun

et al. 2020

ACS Appl. Energy Mater.

View full text Add to dashboard Cite

Most high-quality CdTe thin films are epitaxially grown on single-crystalline substrates through chemical bondings by either molecular beam epitaxy or metalorganic chemical vapor deposition. The epitaxial CdTe films are rarely applied in electronic or optoelectronic devices because of the rigid single-crystalline substrate. We present high-quality CdTe films epitaxially grown on mica by vapor transport deposition process through weak interface interactions. The full width at half-maximum (fwhm) of the X-ray diffraction rocking curve of CdTe ( 111) and the fwhm of azimuthal in-plane angular dispersion of CdTe (111) were 0.23°and 0.36°, respectively. The weak interaction at the interface enables a transfer of the epitaxial film from mica onto other flexible substrates for applications. The epitaxial CdTe film was separated from the mica substrate by the surface tension of water during immersion and then transferred onto a flexible SU-8 photoresist substrate for the fabrication of CdTe solar cells. We successfully fabricated the flexible all-epitaxial, epi-CdS/epi-CdTe solar cells with a power conversion efficiency of 9.59%, which showed low interface defects and high diode quality compared to the poly-CdS/epi-CdTe solar cells.

show abstract

Van der Waals Epitaxy of HgCdTe Thin Films for Flexible Infrared Optoelectronics

Pan

Zhang

et al. 2022

Adv Materials Inter

View full text Add to dashboard Cite

performance, such as fast response, tailorable bandgap over the 1-30 µm range, and high quantum efficiency, HgCdTebased IR photodetectors grown on latticematched Cd 0.96 Zn 0.04 Te (CZT) substrates and associated focal plane arrays (FPAs) dominate the high-performance end of IR applications. [1] The further development of IR applications requires the future HgCdTe IR detectors to have new features of lower cost, larger array format size, higher operating temperature, larger field of view (FOV), and multiband detection. [2] Over the past 10-20 years, significant progress has been achieved in these areas. For example, alternative substrates (Si, Ge, GaAs, and GaSb) instead of the traditional CZT substrates were researched for growing HgCdTe IR materials in order to fabricate nextgeneration IR imaging FPAs with lower cost and larger array format. [3][4][5] Recently curved imaging FPAs have been proposed as a feasible approach for achieving larger FOV with simpler and flatter lenses in comparison to conventional planer FPAs. [2] The conventional development pathway of these curved imaging FPAs relies on substrate thinning and FPA bending, which is inherently limited due to complex device processing, low yield, and high cost. Note that II-VI HgCdTe materials are more vulnerable to damage during the substrate-thinning processes because they are much more fragile and sensitive to chemical/mechanical damage in comparison to conventional Group IV and III-V semiconductors. In addition, the process does not remove the substrate completely due to the variability limits of array alignment on the polishing tool. Consequently, both the flexibility of the thinned FPA and the feasibility of monolithic integration are also limited in comparison to what could be achieved if transferable and/or free-standing HgCdTe device active layer of thickness <10 µm was available.Two-dimensional (2D)-layered materials such as graphene and mica have the potential to serve as substrates for growing high-quality three-dimensional (3D) semiconductor thin films through van der Waals epitaxy (vdWE) techniques such as molecular beam epitaxy (MBE) and MOCVD. [6] For vdWE growth, the stringent requirement of matched lattice constants for highquality heterostructure growth in traditional semiconductor epitaxy is mitigated. This is because the 2D-layered substrates have naturally passivated surfaces and strong chemical bonding is not required at the interface. In this way, the generation of dislocations at the interface can be effectively suppressed. [7,8] Van der Waals epitaxial (vdW) growth of semiconductor thin films on 2D layered substrates has recently attracted considerable attention since it provides a potential pathway for realizing monolithically integrated devices and flexible devices. In this work, direct growth of epitaxial HgCdTe (111) thin films on 2D layered transparent mica substrates is achieved via molecular beam epitaxy. The full width at half maximum of the ω-mode X-ray diffraction peak is measured to be around 306 arc sec. Mid-wave in...

show abstract

Surface and interface of epitaxial CdTe film on CdS buffered van der Waals mica substrate

Cited by 18 publications

References 76 publications

Ultrahigh‐Detectivity Photodetectors with Van der Waals Epitaxial CdTe Single‐Crystalline Films

Ultrahigh‐Detectivity Photodetectors with Van der Waals Epitaxial CdTe Single‐Crystalline Films

Epitaxial CdTe Thin Films on Mica by Vapor Transport Deposition for Flexible Solar Cells

Van der Waals Epitaxy of HgCdTe Thin Films for Flexible Infrared Optoelectronics

Contact Info

Product

Resources

About