High ambipolar mobility in cubic boron arsenide

Abstract

Semiconductors with high thermal conductivity and electron-hole mobility are of great importance for electronic and photonic devices as well as for fundamental studies. Among the ultrahigh–thermal conductivity materials, cubic boron arsenide (c-BAs) is predicted to exhibit simultaneously high electron and hole mobilities of >1000 centimeters squared per volt per second. Using the optical transient grating technique, we experimentally measured thermal conductivity of 1200 watts per meter per kelvin and ambipolar mobility of 1600 centimeters squared per volt per second at the same locations on c-BAs samples at room temperature despite spatial variations. Ab initio calculations show that lowering ionized and neutral impurity concentrations is key to achieving high mobility and high thermal conductivity, respectively. The high ambipolar mobilities combined with the ultrahigh thermal conductivity make c-BAs a promising candidate for next-generation electronics.

Primitive to conventional geometry projection for efficient phonon transport calculations

“…Here, 𝑛 𝑥 = 2, 𝑛 𝑦 = 1, and 𝑛 𝑧 = 1. Going from Γ → M to Γ′ → M′ requires ∆𝐪 = [0, 2𝜋 𝐑 2 , 0] with 𝑔 1 = 0 , 𝑔 2 = 1 , and 𝑔 3 = 0 .Equation(18) in the main text gives ∆𝑙 = −1, which is verified in Fig.S1bwhere phonon dispersions for the two paths are compared. Note that l=-1 is equivalent to l=2.…”

“…Computational studies of material properties, particularly transport phenomena of heat, charge, and mass at micro-and nanoscales 1 , have recently provided accurate quantification of measured observables and fundamental understanding of complex physics, due in large part to increased computational power, theoretical advances, and availability of numerical tools [2][3][4][5][6] . Firstprinciples calculations based on density functional theory (DFT) have demonstrated remarkable power in accurately predicting thermal and electrical properties of semiconductors [7][8][9][10] , for example, the ultrahigh thermal conductivity of cubic BAs and BN [11][12][13][14] , phonon hydrodynamics in graphitic materials [15][16][17] , and high mobility of BAs 18 . Many of these successful simulations have been based on materials with simple structures and compositions.…”

Recent major advances and challenges in the emerging graphene-based nanomaterials in electrocatalytic fuel cell technology

“…Currently, new 2D CMs are being produced by researchers, where the applications of these materials depend on the types of carbon atoms that they possess with a range of morphologies, such as, fullerenes (0D, 1985), 35 carbon nanotubes (1D, CNTs, 1991), 36 and graphene (2D, 2004). 37 Over the past two decades, a variety of carbon allotropes, including CNTs, fullerene (sp 2 ), G (sp 2 ), and diamond (sp 3 ), have been produced via the hybridization of different carbon atoms. Several applications using these materials have been executed successfully.…”

Activated Lone-Pair Electrons Lead to Low Lattice Thermal Conductivity: A Case Study of Boron Arsenide

“…It has been reported that the cubic boron arsenide (c-BAs) has attracted wide attention in electronics, photoelectrics, water decomposition, etc., because the c-BAs is a revolutionary semiconductor with high ambipolar mobilities combined with the ultrahigh thermal conductivity. 5 Previous theoretical studies predicted that cubic boron arsenide (c-BAs) in the bulk form has an exceptionally high κ over 2000 W/mK, which is comparable to the bulk carbon crystals (diamond) with record highest κ. 6 The ultrahigh κ of c-BAs was analyzed to be resulted from the large phonon band gap between acoustic and optical phonon branches together with the bunching of the acoustic phonon branches, which reduce phonon−phonon scattering.…”

“…Lots of potential high ZT materials have limited applications in the thermoelectric field because of high κ, which makes it highly urgent to find an effective approach to lower the intrinsic κ. It has been reported that the cubic boron arsenide ( c -BAs) has attracted wide attention in electronics, photoelectrics, water decomposition, etc., because the c -BAs is a revolutionary semiconductor with high ambipolar mobilities combined with the ultrahigh thermal conductivity . Previous theoretical studies predicted that cubic boron arsenide ( c -BAs) in the bulk form has an exceptionally high κ over 2000 W/mK, which is comparable to the bulk carbon crystals (diamond) with record highest κ .…”