We investigate exponential-based adaptive numerical time integrators
for time-dependent systems of linear ordinary differential equations of
Schrödinger type. Applications in the study of the design of novel solar
cells motivate the interest in finding efficient adaptive time
integration methods for this task. We consider commutator-free
Magnus-type methods, classical Magnus integrators and novel
integrators based on a splitting approach. In all the methods,
efficient time-stepping is realized based on defect-based estimators
for the local error constructed especially for the task. We
show the asymptotical correctness of the error estimators and
demonstrate the advantages of adaptive time-stepping.