Enhanced Hole‐Carrier Selectivity in Wide Bandgap Halide Perovskite Photovoltaic Devices for Indoor Internet of Things Applications

Abstract

Halide perovskite‐based photovoltaic (PV) devices have recently emerged for low energy consumption electronic devices such as Internet of Things (IoT). In this work, an effective strategy to form a hole‐selective layer using phenethylammonium iodide (PEAI) salt is presented that demonstrates unprecedently high open‐circuit voltage of 0.9 V with 18 µW cm−2 under 200 lux (cool white light‐emitting diodes). An appropriate post‐deposited amount of PEAI (2 mg) strongly interacts with the perovskite surface forming a conformal coating of PEAI on the perovskite film surface, which improves the crystallinity and absorption of the film. Here, Kelvin probe force microscopy results indicate the diminished potential difference across the grain boundaries and grain interiors after the PEAI deposition, constructing an electrically and chemically homogeneous surface. Also, the surface becomes more p‐type with a downshift of a valence band maximum, confirmed by ultraviolet photoelectron spectroscopy measurement, facilitating the transport of holes to the hole transport layer (HTL). The hole‐selective layer‐deposited devices exhibit reduced hysteresis in light current density–voltage curves and maintain steadily high fill factor across the different light intensities (200–1000 lux). This work highlights the importance of the HTL/perovskite interface that prepares the indoor halide perovskite PV devices for powering IoT device.

Indoor Perovskite Photovoltaics for the Internet of Things—Challenges and Opportunities toward Market Uptake

“…Moreover, the perovskite‐based long‐chain alkylammonium cation movement toward the HTL is inhibited, especially in the case of low dimensional perovskites. [ 95 ] A record V OC of 0.9 V with an output power of 18 µW cm −2 under 200 Lux (cool white LED) has been reported. In addition, post‐deposited amount of PEAI (2 mg) strongly interacts with the perovskite surface forming a conformal coating of PEAI, which improves the crystallinity and absorption of the film.…”

Energy Solutions for Wearable Sensors: A Review

“…Lee et al tested the indoor performance of a perovskite photovoltaic cell under 200–1000 lux of illumination conditions. This cell realizes 18 power density under 200 lux cool white light, and the fill factor kept stable among the light intensity range [ 47 ]. Biswas et al enhanced the PCE of indoor organic solar cell by studying the doping concentration of the cell’s hole extraction layer.…”

Comparing and Quantifying Indoor Performance of Organic Solar Cells

“…Although efficiencies for indoor organic photovoltaics (iOPV) [ 14–35 ] and other emerging indoor photovoltaics (iPV) technologies such as halide perovskites [ 36–43 ] or dye‐sensitized solar cells [ 44–50 ] have improved substantially, it is hard to quantify progress and determine champion solar cells due to a lack of standardized comparison methods. [ 12,51,52 ] Different authors use different conditions to evaluate the performance of their devices.…”

“…[8][9][10][11][12][13] The possibility to produce solution-based, lowcost, and flexible solar foils makes OPV a good candidate to fulfill this demand. Furthermore, the absorption spectra of the active materials can be tuned chemically to match different light sources.Although efficiencies for indoor organic photovoltaics (iOPV) and other emerging indoor photovoltaics (iPV) technologies such as halide perovskites [36][37][38][39][40][41][42][43] or dye-sensitized solar cells [44][45][46][47][48][49][50] have improved substantially, it is hard to quantify progress and determine champion solar cells due to a lack of standardized comparison methods. [12,51,52] Different authors use different conditions to evaluate the performance of their devices.…”