Measuring the Absorber Doping Concentration of Si, CdSeTe, and Perovskite Solar Cells Using Injection-Dependent Quasi-Steady-State Photoluminescence

Abstract

There are few doping concentration measurement techniques that are contactless and usable for all semiconductors. In this article, we demonstrate the use of injection-dependent quasi-steady-state photoluminescence to simultaneously measure the external radiative efficiency, minority-carrier lifetime, and activated dopant concentration of solar cell absorber layers. We first demonstrate this measurement on Si, for which established lifetime and doping measurement techniques exist, and determine a doping density of 4.2 × 10 ¹⁵ cm ⁻³ , which is within a factor of 2 from the 2.1 × 10 ¹⁵ cm ⁻³ value calculated from quasi-steady state photoconductance. Then, we demonstrate the use of the technique to measure doping concentrations of CdSeTe over two orders of magnitude and of perovskite down to nearly 10 ¹⁴ cm ⁻³ —materials that are much more difficult to accurately assess with other techniques.