Doping diamond exhibits excellent photoelectric properties, making it promising for applications in wide-bandgap semiconductors, high-temperature devices, and high-power electronics. However, research on n-type doping remains limited. This paper reviews the main n-type doping methods for diamond: ion implantation (I/I), chemical vapor deposition (CVD), high pressure–high temperature (HPHT), deuterated method (DM), surface charge transfer doping (SCTD), and laser irradiation (LI). It analyzes the parameters, advantages, and disadvantages of each technique while classifying common single-element and multi-element co-doping methods. Single-element dopants include Group IA (Li, Na, K), Group ⅡA (Be, Mg), Group VA (N, P, As, Sb), and Group ⅥA (O, S, Se, Te) elements. Multi-element co-doping often combines B-P, B-S, B-O, and B-N pairs. Additionally, we examine the atomic structures of these dopants, introduce commonly used simulation models, and compare the electronic characteristics of synthesized n-type doping diamonds. Finally, we summarize the challenges of n-type doping diamond in doping equipment, processes, and electronic devices, and propose possible improvements and future development directions.

Layered LiNi0.83Co0.11Mn0.06O2 cathode materials single- and dual-doped by the rare-earth elements Ce and Nd are successfully fabricated by using a coprecipitation-assisted solid-phase method. For comparison purposes, nondoping pristine LiNi0.83Co0.11Mn0.06O2 cathode material is also prepared using the same method. The crystal structure, morphology, and electrochemical performances are characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) mapping, and electrochemical techniques. The XRD data demonstrates that all prepared samples maintain a typical α-NaFeO2-layered structure with the R-3m space group, and that the doped samples with Ce and/or Nd have lower cation mixing than that of pristine samples without doping. The results of SEM and EDS show that doped elements are uniformly distributed in all samples. The electrochemical performances of all doped samples are better than those of pristine samples without doping. In addition, the Ce/Nd dualdoped cathode material shows the best cycling performance and the least capacity loss. At a 10 C-rate, the electrodes of Ce/Nd dual-doped cathode material exhibit good capacity retention of 72.7, 58.5, and 45.2% after 100, 200, and 300 cycles, respectively, compared to those of pristine samples without doping (24.4, 11.1, and 8.0%).

Tantalum nitrides () have been developed to substitute the Cd based pigments for non-toxic red pigment. Various doping elements were doped to reduce the amount of high price Tantalum element used and preserve the red color tonality. Doping elements were added in the synthesizing process of precursor of amorphous tantalum oxides and then Tantalum nitrides doped with various elements were obtained by ammonolysis process. The average particle size of final nitrides with secondary phases was larger than the nitride without the secondary phases. Also secondary phases reduced the red color tonality of final products. On the other hand, final nitrides without secondary phase had orthorhombic crystal system and presented good red color. In other words, in the case of nitrides without secondary phases, doping elements made a solid solution of tantalum nitride. In this context, doping process controlled the ionic state of nitrides and the amount of oxygen/nitrogen in final nitrides affected the color tonality.