H. Goldsmid, Thermoelectric Refrigeration, 1964.

, Thermoelectrics and its Energy Harvesting, 2012.

H. Wang, A. Lalonde, Y. Pei, and G. J. Snyder, Adv. Funct. Mater, vol.23, p.1586, 2013.

Y. Pei, H. Wang, and G. J. Snyder, Adv. Mater, vol.24, p.6125, 2012.

Y. Lee, S. Lo, J. Androulakis, C. Wu, L. Zhao et al., J. Am. Chem. Soc, vol.135, p.5152, 2013.

J. P. Heremans, V. Jovovic, E. S. Toberer, A. Saramat, K. Kurosaki et al., Science, vol.321, p.554, 2008.

G. Tan, L. Zhao, F. Shi, J. W. Doak, S. Lo et al., J. Am. Chem. Soc, vol.136, p.7006, 2014.

G. Tan, F. Shi, J. W. Doak, H. Sun, L. Zhao et al., Energy Environ. Sci, vol.8, p.267, 2015.

G. Tan, F. Shi, S. Hao, H. Chi, T. P. Bailey et al., J. Am. Chem. Soc, vol.137, p.11507, 2015.

G. Tan, F. Shi, S. Hao, H. Chi, L. Zhao et al., J. Am. Chem. Soc, vol.137, p.5100, 2015.

G. Tan, W. G. Zeier, F. Shi, P. Wang, G. J. Snyder et al., Chem. Mater, vol.27, p.7801, 2015.

Q. Zhang, B. Liao, Y. Lan, K. Lukas, W. Liu et al., Proc. Antl. Acad. Sci. USA, vol.110, p.13261, 2013.

J. He, X. Tan, J. Xu, G. Liu, H. Shao et al., J. Mater. Chem. A, vol.3, p.19974, 2015.

M. Zhou, Z. M. Gibbs, H. Wang, Y. Han, C. Xin et al., Phys. Chem. Chem, p.20

. Phys, , vol.16, p.20741, 2014.

A. Banik, U. S. Shenoy, S. Anand, U. W. Waghmare, and K. Biswas, Chem. Mater, vol.27, p.581, 2015.

A. Banik, B. Vishal, S. Perumal, R. Datta, and K. Biswas, Energy Environ. Sci, vol.9, p.2011, 2016.

R. Orabi, N. A. Mecholsky, J. Hwang, W. Kim, J. Rhyee et al., Chem. Mater, vol.28, p.376, 2016.

R. Orabi, J. Hwang, C. Lin, R. Gautier, B. Fontaine et al., Chem. Mater, vol.29, p.612, 2017.

L. Zhang, J. Wang, Z. Cheng, Q. Sun, Z. Li et al., J. Mater. Chem. A, vol.4, p.7936, 2016.

Z. Zhou, J. Yang, Q. Jiang, Y. Luo, D. Zhang et al., J. Mater. Chem. A, vol.4, p.13171, 2016.

L. Zhao, X. Zhang, H. Wu, G. Tan, Y. Pei et al., J. Am. Chem. Soc, vol.138, p.2366, 2016.

S. Roychowdhury, U. S. Shenoy, U. V. Waghmare, and K. Biswas, J. Mater. Chem. C, vol.5, p.5737, 2017.

W. Li, L. Zheng, B. Ge, S. Lin, X. Zhang et al., Adv. Mater, vol.29, p.1605887, 2017.

L. Wang, X. Tan, G. Liu, J. Xu, H. Shao et al., ACS Energy Lett, vol.2, p.1203, 2017.

L. Zheng, W. Li, S. Lin, J. Li, Z. Chen et al., ACS Energy Lett, vol.2, p.563, 2017.

L. Hu, Y. Zhang, H. Wu, J. Li, Y. Li et al., Adv. Energy Mater, vol.8, p.1802116, 2018.

N. Wang, D. West, J. Liu, J. Li, Q. Yan et al., Phys. Rev. B, vol.89, p.45142, 2014.

J. Q. Li, S. Huang, Z. P. Chen, Y. Li, S. H. Song et al., Phys. Chem. Chem. Phys, vol.19, p.28749, 2017.

R. F. Brebrick and A. J. Strauss, Phys. Rev, vol.131, 1963.

R. F. Brebrick, J. Phys. Chem. Solids, vol.24, p.27, 1963.

J. A. Kafalas, R. F. Brebrick, and A. J. Strauss, Appl. Phys. Lett, vol.4, p.93, 1964.

D. M. Chigikov and V. P. , Schastliviy in Tellure and Tellurides, 1966.

L. M. Rogers, J. Phys. D: Appl. Phys, vol.1, p.845, 1968.

D. J. Singh, Funct. Mater. Lett, vol.3, p.223, 2010.

Y. Tanaka, Z. Ren, T. Sato, K. Nakayama, S. Souma et al., Nat. Phys, vol.8, p.800, 2012.

D. Ibrahim, V. Ohorodniichuk, C. Candolfi, C. Semprimoschnig, A. Dauscher et al., ACS Omega, vol.2, p.7106, 2017.

J. Rodriguez-carvajal, Physica B, vol.192, p.55, 1993.

L. E. Shelimova and N. K. Abrikosov, Russ J Inorg Chem, vol.9, p.1017, 1964.

L. E. Glukhikh and N. K. Abrikosov, Russ J Inorg Chem, vol.8, p.930, 1963.

R. F. Brebrick, J. Electron. Mater, vol.6, p.659, 1977.

R. F. Brebrick and A. J. Strauss, J. Chem. Phys, vol.41, p.197, 1964.

, URL) for additional HRTEM images, detailed analysis of the Mössbauer data, additional transport properties measurements and equations used to model the hole concentration dependence of the hole mobility and the temperature dependence of the lattice thermal conductivity

W. Keune, Phys. Rev, vol.10, p.5057, 1974.

V. A. Bruykhanov, N. N. Delyagin, R. N. Kuz'min, and V. S. Shpinel, Sov. Phys. -JETP, vol.19, p.1344, 1964.

R. D. Taylor and P. P. Craig, Phys. Rev, vol.175, p.782, 1968.

O. Valassiades and N. A. Economou, Phys. Status Solidi A, vol.30, p.187, 1975.

P. B. Littlewood, B. Mihaila, R. K. Schulze, D. J. Safarik, J. E. Gubernatis et al.,

C. P. Rotenberg, T. Opeil, J. L. Durakiewicz, J. C. Smith, and . Lashley, Phys. Rev. Lett, vol.105, p.86404, 2010.

C. D. O'neill, D. A. Sokolov, A. Hermann, A. Bossak, C. Stock et al., Phys. Rev. B, vol.95, p.144101, 2017.

K. L. Kobayashi, Y. Kato, Y. Katayama, and K. F. Komatsubara, Phys. Rev. Lett, vol.37, p.772, 1976.

R. F. Brebrick, J. Phys. Chem. Solids, vol.32, p.551, 1971.

Y. Huang and R. F. Brebrick, J. Electrochem. Soc, vol.135, p.1547, 1988.

Y. I. Ravich, Semiconducting Lead Chalcogenides, 1979.

L. Makowski and M. Glicksman, J. Phys. Chem. Solids, vol.34, p.487, 1973.

V. W. Chin, R. J. Egan, and T. L. Tansley, J. Appl. Phys, vol.69, p.3571, 1991.

J. W. Harrison and J. R. Hauser, Phys. Rev. B, vol.13, p.5347, 1976.

J. R. Hauser, M. A. Littlejohn, and T. H. Glisson, Appl. Phys. Lett, vol.28, p.458, 1976.

G. Nimtz and B. Schlicht, Narrow-Gap Semiconductors, 1983.

, Springer Materials, Landolt-Börnstein Database. Available at www.springermaterials.com

H. Weng, Y. Pei, A. D. Lalonde, and G. J. Snyder, Proc. Nat. Acad. Sci, vol.109, p.9705, 2012.

S. Rabii, Phys. Rev, vol.182, p.821, 1969.

C. M. Jaworski, M. D. Nielsen, H. Wang, S. N. Girard, W. Cai et al.,

J. P. Kanatzidis and . Heremans, Phys. Rev. B, vol.87, p.45203, 2013.

R. W. Mckinney, P. Gorai, V. Stevanovic, and E. S. Toberer, J. Mater. Chem. A, vol.5, p.23, 2017.

M. Thesberg, H. Kosina, and N. Neophytou, Phys. Rev. B, vol.95, p.125206, 2017.

J. Callaway, Phys. Rev, vol.113, p.1046, 1959.