The room-temperature thermoelectric property of PbTe enhanced by mean-free-path filtering

•Without mean free path scattering, the contribution of electrical conductivity is ordered by POP, ADP and IMP.•With electron/hole mean free path scattering, the contribution is ordered by MFP(10 nm), POP, ADP, IMP.•The Normal/Umklapp process dominates the three-phonon scattering/ four-phonon scattering.•For thermal transport of PbTe, the acoustic scattering dominates the scattering channel.•Under mean-free-path filtering, the ZT of p type (0.58) is nearly four times larger than that of bulk ZT (0.15).