TY - JOUR
T1 - Transition metal doping of GaSe implemented with low temperature liquid phase growth
AU - Lei, Nuo
AU - Sato, Youhei
AU - Tanabe, Tadao
AU - Maeda, Kensaku
AU - Oyama, Yutaka
PY - 2017/2/15
Y1 - 2017/2/15
N2 - Our group works on improving the conversion efficiencies of terahertz (THz) wave generation using GaSe crystals. The operating principle is based on difference frequency generation (DFG) which has the advantages such as high output power, a single tunable frequency, and room temperature operation. In this study, GaSe crystals were grown by the temperature difference method under controlled vapor pressure (TDM-CVP). It is a liquid phase growth method with temperature 300 °C lower than that of the Bridgman method. Using this method, the point defects concentration is decreased and the polytype can be controlled. The transition metal Ti was used to dope the GaSe in order to suppress free carrier absorption in the low frequency THz region. As a result, a deep acceptor level of 38 meV was confirmed as being formed in GaSe with 1.4 at% Ti doping. Compared with undoped GaSe, a decrease in carrier concentration (~1014 cm−3) at room temperature was also confirmed. THz wave transmittance measurements reveal the tendency for the absorption coefficient to increase as the amount of dopant is increased. It is expected that there is an optimum amount of dopant.
AB - Our group works on improving the conversion efficiencies of terahertz (THz) wave generation using GaSe crystals. The operating principle is based on difference frequency generation (DFG) which has the advantages such as high output power, a single tunable frequency, and room temperature operation. In this study, GaSe crystals were grown by the temperature difference method under controlled vapor pressure (TDM-CVP). It is a liquid phase growth method with temperature 300 °C lower than that of the Bridgman method. Using this method, the point defects concentration is decreased and the polytype can be controlled. The transition metal Ti was used to dope the GaSe in order to suppress free carrier absorption in the low frequency THz region. As a result, a deep acceptor level of 38 meV was confirmed as being formed in GaSe with 1.4 at% Ti doping. Compared with undoped GaSe, a decrease in carrier concentration (~1014 cm−3) at room temperature was also confirmed. THz wave transmittance measurements reveal the tendency for the absorption coefficient to increase as the amount of dopant is increased. It is expected that there is an optimum amount of dopant.
KW - A1. Point defects
KW - A2. Growth from melt
KW - A3. Liquid phase epitaxy
KW - B1. Gallium compounds
KW - B2. Semiconducting gallium compounds
KW - B3. Nonlinear optical
UR - http://www.scopus.com/inward/record.url?scp=85007369840&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85007369840&partnerID=8YFLogxK
U2 - 10.1016/j.jcrysgro.2016.12.039
DO - 10.1016/j.jcrysgro.2016.12.039
M3 - Article
AN - SCOPUS:85007369840
VL - 460
SP - 94
EP - 97
JO - Journal of Crystal Growth
JF - Journal of Crystal Growth
SN - 0022-0248
ER -