Photoluminescence and Time Resolved Photoluminescence of Organic-inorganic Halide Perovskites*

Organic-inorganic halide perovskites (OIHP), where perovskites layers are separated by organic spacers, can be engineered to have photoluminescence (PL) emissions from UV to IR regions, in addition to power conversion efficiencies of more than 24%. This class of materials offers broad tunability through controlling the number of atomic layers in the quantum well via perovskite composition and the spacer thickness depending on what organic groups are incorporated. In this work we present PL and time resolved PL (TRPL) measurements of these materials as a function of temperature and magnetic field, including: BA₂PbI₄, BA₂MA₁Pb₂I₇, and BA₂CuCI₄ where BA₂ represents (CH₃(CH₂)₃NH₃)₂, and MA: CH₃NH₃. Both BA₂PbI₄ and BA₂CuCI₄ have a single layer of perovskite material separated by an organic cation layer while BA₂MA₁Pb₂I₇ has two atomic layers of perovskite. Our observations indicate the existense of both free and trapped excitons.