Is diamond a negative electron-affinity material?

Answer 1

Diamond is an unique material, which can exhibit both negative and positive electron affinities. A clean diamond surface yields a positive electron affinity of around 0.6 eV. In contrast, hydrogenated and hydroxylated diamond surfaces exhibit negative electron affinities of -1.1 and -2.13 eV, respectively. Moreover, halogenated diamond surfaces give positive electron affinities. Hope this will help :-)

Answer 2

Yes, diamond is considered a negative electron-affinity material because it tends to release energy when gaining an extra electron, indicating a lower affinity for electrons.