Bandwidth and band filling control in organic conductors

in order to search and clarify the mechanism of organic superconductors, it is of importance to control the electronic state systematically and elucid ate the electronic phase diagram. In organic conductors, bandwidth control is usually applied to change the electronic states from insulating, superco nducting, to metallic state. By the chemical bandwidth control with introdu cing Se atoms, the antiferromagnetic insulator, lambda -ET2GaCl4, newly pre pared, shifts to the semi-conductor, lambda-(us-BEDT-STF)(2)GaCl4, and supe rconductor, lambda -BETS2GaCl4. It is clarified that lambda -type organic s uperconductor has been obtained by the chemical bandwidth control of the an tiferromagnetic insulator. In this paper, our recent successful results of band filling control in organic conductors are also reported. (C) 2001 Else vier Science B.V. All rights reserved.