Systematics in the optical and electronic properties of the binary lanthanide halide, chalcogenide and pnictide compounds: An overview

The basic optical, electrical and chemical properties of the binary divalent, trivalent and tetravalent lanthanide (Ln = La, . . . , Lu) halides (F, Cl, Br and I), chalcogenides (O, S, Se and Te) and pnictides (N, P, As and Sb) were studied using an empirical model that utilizes the systematic behaviour in the energy difference between the...

Lanthanide 4f-level location in AVO4:Ln3+ (A = La, Gd, Lu) crystals

The spectral properties of LaVO4, GdVO4 and LuVO4 crystals doped with Ce3+, Pr3+, Eu3+ or Tb3+ have been investigated in order to determine the position of the energy levels relative to the valence and conduction bands of the hosts along the trivalent and divalent lanthanide series. Pr3+ and Tb3+ ground state levels are positioned based on the...

The thermally induced metal–semiconducting phase transition of samarium monosulfide (SmS) thin films

High quality phase pure samarium monosulfide (SmS) thin films were prepared by electron beam evaporation using a samarium metal source in a H2S atmosphere. The optical properties (reflection, transmission, absorption) of the films in the semiconducting and metallic phase were analysed from the UV to the mid-IR and explained in terms of the...

Controlled electron and hole trapping in YPO4:Ce3+,Ln3+ and LuPO4:Ce3+,Ln3+ (Ln=Sm, Dy, Ho, Er, Tm)

A detailed and systematic electron trapping study was conducted in the scientifically important wide band-gap materials LuPO4 and YPO4 doubly doped with Ce3+ and Ln3+ (Ln=Sm, Dy, Ho, Er, Tm). By using vacuum-ultraviolet luminescence spectroscopy and detailed thermoluminescence spectroscopy it was possible to establish by two independent methods...

Lanthanide 4f-level location in lanthanide doped and cerium-lanthanide codoped NaLaF4 by photo- and thermoluminescence

Photo- and thermoluminescence (TL) spectra of NaLaF4:Ln3+ (Ln = Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Ho,Er,Tm) and NaLaF4:Ce3+, Ln3+ (Ln = Nd,Sm,Ho,Er,Tm) are presented and used together with the empirical Dorenbos model in order to establish the 4f energy level positions of all tri- and divalent lanthanide ions doped in NaLaF4. The information will be...

High-resolution luminescence spectroscopy study of down-conversion routes in NaGdF4:Nd3+ and NaGdF4:Tm3+ using synchrotron radiation

Luminescence quenching by photoionization and electron transport in a LaAlO3:Ce3+ crystal

A combined photoconductivity, absorption, and thermoluminescence study was performed to understand the absence of luminescence from Ce3+ in LaAlO3:Ce3+. It is demonstrated that the absence of luminescence is the result of Ce3+ ionization from the 5d excited states, which are all located in the conduction band. Ce3+ ionization is accompanied by...

Systematic and material independent variation of electrical, optical, and chemical properties of Ln-materials over the Ln-series (Ln=La,Ce,Pr,..,Lu)

A model is presented that successfully predicts electro-optical properties of Lanthanide materials, irrespective whether these materials are inorganic or organic, diluted or concentrated, metallic, semi-conducting or insulating. The model is firmly based on recent experimental data revealing that the variation in 4f and 5d energies relative to...

Lanthanide impurity level location in GaN, AlN, and ZnO

A method that has proven succesful in locating the energy levels of divalent and trivalent lanthanide ions (Ce, Pr,..., Eu,...Yb, Lu) in wide band gap inorganic compounds like YPO4 and CaF2 is applied to locate lanthanide levels in the wideband semiconductors GaN, AlN, their solid solutions AlxGa1-xN, and ZnO. The proposed schemes provide a...

Location of lanthanide impurity levels in the III-V semiconductor GaN

Knowledge from lanthanide spectroscopy on wide band gap (6–10?eV) inorganic compounds is used to understand and predict optical and electronic properties of the lanthanides in the III-V semiconductor GaN. For the first time the location of the 4fn ground state energy of each divalent and trivalent lanthanide ion relative to the valence and...