“…At last, a discussion of future possible strategies is proposed to aim at further enhancing the thermoelectric performance in PbTe-based materials. PbTe-Ge:Na, 101 (2) PbTe:(Na, Bi), 102 (3) PbTe-Sn:(Ag, Sb), 103 (4) PbTe-Mn:Na, 104 (5) PbTe-Se:K, 105 (6) PbTe-Ca:Na, 91 (7) PbTe-Cd:Na, 92 (8) PbTe-S:K, 61 (9) PbTe:Na, 106 (10) PbTe:Na (Nano-precipitates), 107 (11) PbTe-Ge, 108 (12) PbTe-Se-S:Na, 109 (13) PbTe-Hg: Na, 110 (14) PbTe:Tl, 64 (15) PbTe-Sn-Se-S: Na, 95 (16) PbTe-Yb:Na, 111 (17) PbTe-Se:Na, 62 (18) PbTe-Mn-Sr:Na, 112 (19) PbTe-Mg:Na, 60 (20) PbTe-Eu:Na, 113 (21) PbTe-Sr:Na, 59 (22) PbTe-S:Na, 63 (23) PbTe-Sr:Na (Non-equilibrium); 53 d peak ZT values as a function of optimized carrier density in n-type PbTe systems: (1) PbTe-Se:Cr, 114 (2) PbTe-Se-S:I, 115 (3) PbTe-NaCl, 116 (4) PbTe-Zn:I, 117 (5) PbTe-Cd:I, 118 (6) PbTe-Sn-Se:I, 119 (7) PbTe-Mg:I, 120 (8) PbTe-Se-S:Cl, 121 (9) PbTe:Cd, …”