[en] Very few thermoluminescent materials are tissue equivalent with an effective atomic number which is very close to that of soft biological tissue (7.4). Lithium borate based TL dosemeters appeared to be the most attractive, with an effective atomic number Zeff=7.3. The first TL material based on Lithium borate which was introduced in radiation dosimetry, was Li₂B₄O₇:Mn phosphor with low TL sensitivity caused partly by the emission in the 600 nm region of the spectra, far from the response region of most photomultipliers. The use of copper activator instead of manganese in lithium borate overcome the drawback of poor TL sensitivity and red TL emission spectra to an emission spectrum of copper activator, at about 360 nm. However, commercially available Li₂B₄O₇:Cu thermoluminescent material is produced in powder form which is inconvenient for routine dosimetric use, or built in Panasonic TLD badges, specially designed for Panasonic TLD System. There are a number of problems to overcome to make Li₂B₄O₇:Cu feasible for routine dosimetric use. Different methods of preparing this TL material have been developed giving rather different TL characteristics, i.e. glow curves, TL sensitivity, linearity, etc. At the Institute of Nuclear Sciences, Vinca, it was developed Li₂B₄O₇:Cu, Li₂B₄O₇:Cu,In and Li₂B₄O₇:Cu,In,Ag, tissue equivalent TL detectors in form of sintered pellets, with the TL sensitivity nearly to that of LiF (TLD-100), feasible for routine dosimetry measurements. However, as a result of an advancement in the preparation procedure by sensitizing of basical Li₂B₄O₇:Cu TL material, significant improvement in the TL sensitivity was gained, by the development of Li₂B₄O₇:Cu,Ag,P TL material. Chemical and isotopic composition of lithium borate TL material enables the preparation of a pair of neutron sensitive, 6^Li₂ 1^0B₄O₇:Cu,Ag,P and neutron unsensitive 7^Li₂ 1^1B₄O₇:Cu,Ag,P TL detectors, for separate measurements of neutron and gamma doses in mixed neutron and gamma radiation fields. It is also prepared carbon loaded Li₂B₄O₇(C):Cu,Ag,P TL detectors in form of sintered pellets with an effective thickness of about 2mg · cm^-2 which fulfilled the requirement of high TL response to weakly penetrating radiation. This paper presents the main dosimetric properties of newly prepared tissue equivalent highly sensitive Li₂B₄O₇:Cu,Ag,P solid TL detectors and also the TL characteristics of 6^Li₂ 1^0B₄O₇:Cu,Ag,P, 7^Li₂ 1^1B₄O₇:Cu,Ag,P, and of Li₂B₄O₇(C):Cu,Ag,P sintered TLD pellets