Controlled spalling of single-crystal semiconductors is an emerging technique which results in the rapid exfoliation of a thin, single-crystal layer by propagating fracture parallel to the wafer surface. Spalling fracture has been engineered to controllably and intentionally exfoliate thin film electronic devices from single-crystal semiconductors for the purposes of creating flexible devices or enabling substrate reuse to mitigate costs. The process uses an adhered stressor layer combined with an externally applied mechanical force to initiate and propagate a lateral fracture parallel to the substrate surface. Proof-of-principle device demonstrations have been achieved at wafer scale and in multiple configurations, showing no loss of performance compared to conventionally processed devices while preserving the wafer for reuse, reclaim, or recycling for cost and material savings. In this talk, examples will be drawn mainly from spalling (100)-oriented Ge and GaAs to illustrate the impact of cleavage system alignment on the resulting fracture morphology and spalling conditions and will include single junction photovoltaic device data.