Polycrystalline CdSeTe/CdTe Absorber Cells With 28 mA/cm² Short-Circuit Current

Understanding the role of selenium in defect passivation for highly efficient selenium-alloyed cadmium telluride solar cells

“…This creates a CdSe(x)Te(1-x) (CdSeTe) alloy that lowers the material bandgap, increases absorption in the long wavelength part of the spectrum, and increases device short-circuit current density [6]- [8]. However, in addition to improved current generation, selenium alloying maintains or improves open circuit voltages -despite the lower bandgap [9]. Recent studies have shown that this is associated with improved minority carrier lifetimes in the absorber, but it is not known why the lifetimes increase [9]- [11].…”

“…However, in addition to improved current generation, selenium alloying maintains or improves open circuit voltages -despite the lower bandgap [9]. Recent studies have shown that this is associated with improved minority carrier lifetimes in the absorber, but it is not known why the lifetimes increase [9]- [11].…”

Analysis of a novel CuCl2 back contact process for improved stability in CdTe solar cells

“…There is evidence that similar processes have been already applied in some laboratories but without a study of the process' effect. [24][25][26][27][28] Beach et al suggested that the defects induced by CdCl 2 , probably Cl-induced donor, increased the solubility of the Cu at Cd substitutional sites impurities Cu − Cd , which are considered acceptors. 29 The CuCl 2 is applied after the standard CdCl 2 activation treatment because combining activation treatment and copper doping in a single step is not possible: CdCl 2 activation treatment is applied at a temperature which would cause a very large Cu diffusion.…”

Kinetic Simulations of Cu Doping in Chlorinated CdSeTe PV Absorbers

“…The recent advances in the CdTe‐based thin‐film photovoltaic (PV) were in part triggered by introduction of graded CdSeTe absorbers (bandgap grading from 1.4 to 1.5 eV), which resulted in a strong increase of the collected photocurrent without compromising the open‐circuit voltage . A typical fabrication process of a thin‐film CdTe‐based PV device includes a recrystallization‐passivation anneal in the chlorine ambient at 400–450 °C followed by the formation of p‐type absorber doping using diffusion‐activation anneal of Cu at 200–300 °C.…”

“…The recent advances in the CdTe-based thin-film photovoltaic (PV) were in part triggered by introduction of graded CdSeTe absorbers (bandgap grading from 1.4 to 1.5 eV), which resulted in a strong increase of the collected photocurrent without compromising the open-circuit voltage. [1,2] A typical fabrication process of a thin-film CdTe-based PV device includes a recrystallization-passivation anneal in the chlorine ambient at 400-450 C followed by the formation of p-type absorber doping using diffusion-activation anneal of Cu at 200-300 C. Being employed for decades to form the p-type doping in chlorinated CdTe absorbers, [3] Cu remains the dopant of choice for the new CdSeTe technology. Yet, detailed physical understanding of the formation and stability of Cu doping in CdTe-based PVabsorbers is still a topic of scientific discussions.…”