Why PH3, H₂S, H₂Se, H₂Te, AsH₃ do not undergo hybridization ?

Dear student
 
In hybridisation we need to have bonding orbitals which have similar energy. The central atom here have vacant d-orbital due to which even when small amount of energy is given out the electrons excite to d-orbitals and can participate in d$\pi$ -p$\pi$  bonding.
In the case of PH₃ , H₂S , AsH₃ etc. the central atom being non-metal have almost have similar electronegativity as that of hydrogen atom.  Hence they don't undergo hybridisation.
Regards