Qucs is a GPL circuit simulator. And if you want the GUI option, you might want to try out QucsStudio, which uses Qucs under the hood, and is free to use, but binary-only.

The ct.qmat team have employed the PT symmetry to still make the open circuit system with gain and loss share a large amount of features with an isolated system.

BGE reviews several alternatives for a battery open-circuit monitoring device to protect from a dc supply single point of failure. The Federal Energy Regulatory Commission issued Order 867 on Jan. 23, ...

Japanese researchers claim that tin sulfide solar cells could achieve higher open-circuit voltages by preventing "Fermi level pinning" from occurring, due to the addition of a tin sulfide ...

Das Solar has achieved a world-record open-circuit voltage of 730 mV for an M10 n-type tunnel oxide passivated contact (TOPCon) solar cell, with a power conversion efficiency of 26.24%, according ...