Charge Carrier Doping into the Peierls Insulator of the TCNQ Anion Radical Salt (TCNQ = 7,7,8,8-Tetracyanoquinodimethane)

详细信息    查看全文

• 作者：Hiroyuki Kubota ; Yukihiro Takahashi ; Hiroyuki Hasegawa ; Takuro Shimada ; Jun Harada ; Tamotsu Inabe
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：June 2, 2016
• 年：2016
• 卷：120
• 期：21
• 页码：11545-11551
• 全文大小：464K
• 年卷期：0
• ISSN：1932-7455

文摘

Hole-doping into K–TCNQ (TCNQ = 7,7,8,8-tetracyanoquinodimethane) crystals with segregated TCNQ anion radical columns with dimeric deformation (Peierls state) has been performed by a contact doping method using F₄TCNQ (F₄TCNQ = 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane) crystals or powder. The sheet resistance of the K–TCNQ surface has been found to decrease by the F₄TCNQ contact. Formation of K–F₄TCNQ nanocrystals at the contact interface has been observed, but conductive AFM images indicate that current paths form along the hole-doped K–TCNQ surface. Interestingly, hole-doping into K–TCNQ suppresses the phase transition to the high-temperature phase (Mott insulator). This is considered to result from the energy gain by the delocalization of the doped carriers.