info:eu-repo/semantics/article
Wavelength dependence of the photo-electromotive-force effect in CdTe:V crystal with bipolar photoconductivity
Autor
SERGUEI STEPANOV
PONCIANO RODRIGUEZ MONTERO
SVETLANA MANSUROVA SERGUEYEVNA
Resumen
We report on detailed investigation of the photo-electromotive-force (photo-EMF) effect in semiconductor with bipolar photoconductivity
of impurity type in a spectral region close to the fundamental absorption edge, where both the photoconductivity and the photo-
EMF response reach their maxima. The experiments performed with CdTe:V crystal (ΔE ≈
1.51 eV) in the spectral range of 826–853 nm
show that dynamics of the photo-EMF signal formation in this crystal is governed by relaxation of slow majority photocarriers–holes
with the life-time which goes down from ƭ ≈ 9 ls at 850 nm to ≈ 6.5 ls at 826 nm. The minority photocarriers (electrons), which contribute
approximately 10% of the total photoconductivity, also demonstrate significant wavelength dependence of their diffusion length with
LD ≈ 8.5 lm at 850 nm and ≈ 6.3 lm at 830 nm. The reported results show significant improvement in responsivity of the bipolar CdTe:V
photo-EMF detector when it is operated at λ = 840 nm (by factor ≈ 2.5 as compared with that at 852 nm).