Superlight and Superflexible Three-Dimensional Semiconductor Frameworks A(X≡Y)4 (A=Si, Ge; X/Y=C, B, N) with Tunable Optoelectronic and Mechanical Properties from First-Principles.

Silicon carbide materials, as leading wide band gap semiconductors, hold significant importance in semiconductor technologies. Herein, diamond-like 3D materials with low density, but high elasticity properties, have been designed from first-principles calculations. They are porous single-crystalline materials composed of sp3 -hybridized silicon (or germanium) and sp-type C≡C (or B≡N) linear moieties; their stabilities are comparable to those of recently prepared SiC4 materials. Moreover, such wide band gap semiconductors have strong absorption over a wide UV range and exhibit superlight, superflexible, and incompressible mechanical properties, and their optoelectronic and mechanical properties can be well tuned through structural modifications. Such features provide high potential for practicable application under extreme conditions, and suggest promising applications for the design of UV optoelectronic devices.