@Article{OkazakiAbraRapp:2020:StCaPb,
               author = "Okazaki, Anderson Kenji and Abramof, Eduardo and Rappl, Paulo 
                         Henrique de Oliveira",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)}",
                title = "Study of caf2-doped pbte thin films grown by molecular beam 
                         epitaxy",
              journal = "Materials Science Forum",
                 year = "2020",
               volume = "1012",
                pages = "136--140",
             keywords = "Lead telluride, calcium fluoride, molecular beam epitaxy, 
                         electrical characterization, structural characterization.",
             abstract = "We present here a study on the electrical and structural 
                         properties of p-type PbTe films doped with CaF2. The layers were 
                         grown by molecular beam epitaxy on freshly cleaved (111) BaF2 
                         substrates. The doping level was monitored by the CaF2 solid 
                         source cell temperature (TCaF2), which varied from 500 to 1150 °C. 
                         The films with low doping level, TCaF2 \≤ 1010 °C, 
                         exhibited flat surfaces with crystalline quality close to the 
                         undoped PbTe sample. In contrast, samples with high levels of 
                         doping (TCaF2 > 1010 °C) presented CaF2 agglomerates on the 
                         surface and a worse crystal quality. The hole density at 77 K 
                         versus TCaF2 oscillated between 1.3 × 1017 and 3.6 × 1017 cm-3 and 
                         did not exhibit a systematic behavior as the fluoride supply is 
                         raised. The results indicate that CaF2 is not an effective p-type 
                         dopant for PbTe, due to the abscence of a resonant level close to 
                         the valence band or to compensation of extrinsic dopant levels.",
                  doi = "10.4028/www.scientific.net/MSF.1012.136",
                  url = "http://dx.doi.org/10.4028/www.scientific.net/MSF.1012.136",
                 issn = "0255-5476",
             language = "en",
           targetfile = "okazaki_study.pdf",
        urlaccessdate = "13 maio 2024"
}