Investigation of Nano‐Gaps in Fractured β‐Ga₂O₃ Nanomembranes Formed by Uniaxial Strain

Abstract

A free‐standing β‐Ga2O3, also called β‐Ga2O3 nanomembrane (NM), is an important next‐generation wide bandgap semiconductor that can be used for myriad high‐performance future flexible electronics. However, details of structure‐property relationships of β‐Ga2O3 NM under strain conditions have not yet investigated. In this paper, the electrical properties of β‐Ga2O3 NM under different uniaxial strain conditions using various surface analysis methods are systematically investigated and layer‐delamination and fractures are revealed. The electrical characterization shows that the presence of nanometer‐sized gaps between fractured pieces in β‐Ga2O3 NM causes a severe property degradation due to higher resistance and uneven charge distribution in β‐Ga2O3 NM which is also confirmed by the multiphysics simulation. Interestingly, the degraded performance in β‐Ga2O3 NM is substantially recovered by introducing excessive OH‐bonds in fractured β‐Ga2O3 NM via the water vapor treatment. The X‐ray photoelectron spectroscopy study reveals that a formation of OH‐bonds by the water vapor treatment chemically connects nano‐gaps. Thus, the treated β‐Ga2O3 samples exhibit reliable and stable recovered electrical properties up to ≈90% of their initial values. Therefore, this result offers a viable route for utilizing β‐Ga2O3 NMs as a next‐generation material for a myriad of high‐performance flexible electronics and optoelectronic applications.

Flexible gallium oxide electronics

“…Thus, it is challenging to grow them directly on conventional flexible polymer substrates. A straightforward strategy to fabricate flexible β-Ga 2 O 3 electronics is to use the transfer technique in which bulk single-crystalline β-Ga 2 O 3 is first obtained using conventional high-temperature growth routes and β-Ga 2 O 3 thin films are then exfoliated from bulk materials and pasted on flexible polymer substrates [90][91][92][93][94][95][96][97]. Single-crystalline β-Ga 2 O 3 has been commonly obtained using the Czochralski method, in which Ga 2 O 3 powders are melted in an iridium crucible at a temperature of >1820 • C in an oxygen-deficient atmosphere [98].…”

High‐Performance Solar Blind UV Photodetectors Based on Single‐Crystal Si/β‐Ga2O3 p‐n Heterojunction

“…Yixiong Zheng, Md Nazmul Hasan, and Jung-Hun Seo* DOI: 10.1002/admt.202100254 tion. [7][8][9] Among these UWBG semiconductors, beta phase Ga 2 O 3 (β-Ga 2 O 3 ) has attracted intensive attention as a promising candidate for DUV PDs due to its desirable material properties such as a bandgap of 4.9 eV, excellent mechanical and thermal stability, and availability of large substrate up to 2 inch [10][11][12][13][14] . However, two imperative issues in β-Ga 2 O 3 are: (i) absence of p-type dopant and (ii) unbalanced electron and hole mobility.…”

“…[ 5 , 6 ] On the other hand, ultra‐wide bandgap (UWBG) semiconductors, such as aluminum gallium nitride (AlGaN), gallium oxide (Ga 2 O 3 ), and diamond, allow us to realize solar‐blind photodetection without adding any additional optical parts by directly using an electron‐hole pair by photon generation. [ 7–9 ] Among these UWBG semiconductors, beta phase Ga 2 O 3 (β‐Ga 2 O 3 ) has attracted intensive attention as a promising candidate for DUV PDs due to its desirable material properties such as a bandgap of 4.9 eV, excellent mechanical and thermal stability, and availability of large substrate up to 2 inch [ 10–14 ] . However, two imperative issues in β‐Ga 2 O 3 are: (i) absence of p‐type dopant and (ii) unbalanced electron and hole mobility.…”

A Review on Gallium Oxide Materials from Solution Processes

“…Because of nanoscale size in at least one dimension, nanomaterials have a high aspect ratio, which leads to high activity and some unique quantum-dimensional effects [ 8 ]. UV photodetectors [ 9 , 10 ], photocatalysis [ 11 ], flat panel display [ 12 ], UV filter [ 13 ], MOS capacitor [ 14 ], MOS structure [ 15 ] and optoelectronic devices [ 16 , 17 ] are some of the applications of Ga 2 O 3 .…”