A semiconductor device comprises a stack comprising an alternating sequence of dielectric structures and conductive structures, and a channel structure within an opening vertically extending through the stack and comprising a first semiconductor material having a first band gap. The semiconductor device also comprises a conductive plug structure within the opening and in direct contact with the channel region, and a band offset structure within the opening and in direct physical contact with the channel structure and the conductive plug structure. The band offset structure comprises a second semiconductor material having a second band gap different than the first band gap. The semiconductor device further comprises a conductive line structure electrically coupled to the conductive plug structure. A method of forming a semiconductor device and an electronic system are also described.