NOVELTY - Thermoelectric device comprises a first electrode; a second electrode; and an electrical transmission medium electrically connected to the first and second electrodes, where the electrical transmission medium comprises a quantum conductor that exhibits at least one transmission node or a transmission resonance due to quantum interference.    USE - The thermoelectric device is useful for producing thermoelectric power generator for generating voltage difference between first electrical contact and second electrical contact in response to temperature difference between first heat-transfer surface and second heat-transfer surface; Peltier cooler for transferring heat from low-temperature surface to high-temperature surface in response to applied voltage between first electrical contact and second electrical contact; and assembly (all claimed).    ADVANTAGE - Thermoelectric devices employing such single-molecule junctions (SMJs) offer superior efficiency and performance. The enhanced thermoelectric response is not limited to only SMJs, but may be obtained from any junction exhibiting transmission nodes or resonances arising from coherent electronic transport.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are:    (1) a thermoelectric power generator for generating a voltage difference between a first electrical contact and a second electrical contact in response to a temperature difference between a first heat-transfer surface and a second heat-transfer surface, comprising at least one N-type thermoelectric structure comprising N-type organic molecules arranged in a self-assembled monolayer; and at least one P-type thermoelectric structure comprising P-type organic molecules arranged in a self-assembled monolayer, where the at least one N-type thermoelectric structure and the at least one P-type thermoelectric structure are electrically connected in series between the first and second electrical contacts and thermally connected in parallel between the first and second heat-transfer surfaces;    (2) a Peltier cooler for transferring heat from a low-temperature surface to a high-temperature surface in response to an applied voltage between a first electrical contact and a second electrical contact, comprising at least one N-type thermoelectric structure comprising N-type organic molecules arranged in a self-assembled monolayer; and at least one P-type thermoelectric structure comprising P-type organic molecules arranged in a self-assembled monolayer, where the at least one N-type thermoelectric structure and the at least one P-type thermoelectric structure are electrically connected in series between the first and second electrical contacts and thermally connected in parallel between the low-temperature and high-temperature surfaces;    (3) a benzene compound of formula 1; and    (4) an assembly comprising a first metal surface; a second metal surface; and one or more molecules bridging the first and second metal surfaces, where each molecule is of benzene of formula 1, where for each molecule bridging the first metal surface and second metal surface, one RE group of the molecule is chemically bonded or associated with the first metal surface, and the second RE group of the molecule is chemically bonded or associated with the second metal surface.    n=1-100;    Z=a bond, -O-, -S-, -N(RZ)-, -C(O)-, -S(O)-, -S(O)2-, -C(RZ)2-, -C(RZ)=C(RZ)-, or -C-triple bond-C-;    RZ=independently hydrogen or 1-6C alkyl;    m=independently 0, 1, 2, 3, or 4;    R=independently an electron-donating group, an electron-withdrawing group, or a group electrically similar to hydrogen;    L=independently a bond or a divalent linking group; and    RE=independently a functional group capable of bonding to or associating with a metal surface.