Direct evidence for bulk photovoltaic charge transport in a ferroelectric polycrystalline film

Growth of p/n-type BiFeO3 thin films for construction of a bilayer p–n junction for photodegradation of organic pollutants

“…It is well known that remnant polarization in ferroelectrics can facilitate the separation of photoexcited charge carriers, which has been exploited for photovoltaic applications. [35][36][37][38][39][40][41] However, in the polycrystalline samples, the remnant polarizations are randomly oriented and therefore they cancel out each other. So, before poling, the charge separation is done almost solely by the p-n junction.…”

“…8(b) are −0.79 V and 59 mA cm −2 , respectively, which are large compared to many of the reported values of V OC and J SC measured with a single layer of various BFO lms. [38][39][40][41] This may be attributed to a more effective separation of photoexcited charge carriers by the dual actions of both the p-n junction and the net remnant polarization.…”

Shift Current with Gaussian Basis Sets and General Prescription for Maximally Symmetric Summations in the Irreducible Brillouin Zone

“…In this regard, the emergence of a direct charge current in a homogeneous material induced by light is known as the bulk photovoltaic effect (BPVE) . It was established by the mid-seventies with earlier experimental reports in ferroelectric materials, − and continued gathering attention during the next decades. − However, the potential applications in solar cells , and the advances in both experimental facilities and first-principles capabilities have driven a considerable surge of studies in recent years. − …”

Narrow Bandgap Inorganic Ferroelectric Thin Film Materials

“…Ferroelectric domains exist in the ferroelectric phase of ferroelectric materials. [ 21 ] For example, there are regularly arranged 109° and 71° oriented domain walls in the microstructure of BiFeO 3 (BFO) materials. The domain wall theory suggests that a maximum open‐circuit voltage ( V oc ) of 5.4 V can be obtained only when the electrodes of the device are oriented parallel to the ferroelectric domain walls in the material, while the value of the perpendicular open circuit voltage is almost zero.…”