GaAs (with a band gap= 1.5 eV) as an LED can emit

Question

GaAs (with a band gap= 1.5 eV) as an LED can emit (A) blue light (B) ultraviolet rays (C) X-rays (D) infrared rays

Tardigrade Admin · Accepted Answer

The band gap= l.5 e V =1.5 × 1.6 × 10-19 J =2.40 × 1-19 J Wavelength of radiation emitted (λ) =(hc/E) =(6.6 × 10-34 × 3 × 108/ 2.4 × 10-19) =8.25 × 10-7 m =8250 mathringA This wavelength belongs to infrared rays.

Q. GaAs (with a band gap= 1.5 eV) as an LED can emit

blue light

ultraviolet rays

X-rays

infrared rays

The band gap= l.5 e V =1.5×1.6×10−19J =2.40×1−19J Wavelength of radiation emitted (λ)=Ehc​ =2.4×10−196.6×10−34×3×108​ =8.25×10−7m =8250A˚ This wavelength belongs to infrared rays.