Investigation of Sub-Bandgap Emission and Unexpected n-Type Behavior in Undoped Polycrystalline CdSeTe.

Se alloying has enabled significantly higher carrier lifetimes and photocurrents in CdTe solar cells, but these benefits can be highly dependent on CdSeTe processing. This work evaluates the optoelectronic, chemical, and electronic properties of thick (3 µm) undoped CdSeTe of uniform composition and varied processing conditions (CdSeTe evaporation rate, CdCl anneal, Se content) chosen to reflect various standard device processing conditions. Sub-bandgap defect emission is observed, which increased as Se content increased and with "GrV-optimized CdCl" (i.

SnO-Catalyzed Oxidation in High-Efficiency CdTe Solar Cells.

Interfaces at the front of superstrate CdTe-based solar cells are critical to carrier transport, recombination, and device performance, yet determination of the chemical structure of these nanoscale regions has remained elusive. This is partly due to changes that occur at the front interfaces during high temperature growth and substantive changes occurring during postdeposition processing. In addition, these buried interfaces are extremely difficult to access in a way that preserves chemical information.

Thermomechanical Lift-Off and Recontacting of CdTe Solar Cells.

Controlled delamination of thin-film photovoltaics (PV) post-growth can reveal interfaces that are critical to device performance yet are poorly understood because of their inaccessibility within the device stack. In this work, we demonstrate a technique to lift off thin-film solar cells from their glass substrates in a clean, reproducible manner by first laminating a polymeric backsheet to the device and then thermally shocking the system at low temperatures ( T ≤ -30 °C). To enable clean delamination of diverse thin-film architectures, a theoretical framework is developed and key process control parameters are identified.