Propylammonium lead iodide (C3H7NH3PbI3), a promising hybrid perovskite, is successfully synthesized by a solgel technique. Structural, optical, and dielectric properties have been studied in detail. The dielectric constant, loss factor, electric modulus, and AC and DC conductivity of this hybrid perovskite exhibit strong temperature dependence over the frequency range of 10 Hz ≤ f ≤ 8 MHz. The Nyquist plot reveals the distinct contributions of grain and grain boundary to the total impedance. The dielectric constant is found to increase with temperature in the high frequency region. The modified Cole–Cole plot shows that the space charge and free charge conductivity increase with the elevation of temperature, whereas the relaxation time decreases with the rise in temperature. From the modified Kohlrausch–Williams–Watts equation, we perceived asymmetrical nature in electric modulus spectra at various temperatures, which corresponds to the non-Debye type nature of perovskite. It has also been found that, with the elevation of temperature, the imaginary part of electric modulus spectra shifts from the non-Debye type toward the Debye type nature, though failing to acquire exact Debye type response, and emerges as a semiconductor material. AC conductivity of PAPbI3 is illustrated on the basis of the correlated barrier hopping (CBH) mechanism. Activation energy estimated from both modulus spectra and DC conductivity matches well, affirming the similarity between relaxation behavior and conduction mechanism. Along with all these, PAPbI3 possesses a high dielectric constant associated with a small dielectric loss, making it a potential candidate for energy harvesting devices.

中文翻译：

---

C3H7NH3PbI3 的温度和频率相关介电响应：一种新型混合钙钛矿

丙铵碘化铅（C3H7NH3PbI3）是一种很有前途的杂化钙钛矿，通过溶胶凝胶技术成功合成。已经详细研究了结构、光学和介电特性。这种混合钙钛矿的介电常数、损耗因数、电模量以及交流和直流电导率在 10 Hz ≤ f ≤ 8 MHz 的频率范围内表现出强烈的温度依赖性。奈奎斯特图揭示了晶粒和晶界对总阻抗的不同贡献。发现介电常数在高频区域随温度增加。修正的 Cole-Cole 图显示空间电荷和自由电荷电导率随温度升高而增加，而弛豫时间随温度升高而减少。从修正的 Kohlrausch-Williams-Watts 方程，我们在不同温度下的电模量谱中发现了不对称性质，这对应于钙钛矿的非德拜型性质。还发现，随着温度的升高，电模量谱的虚部从非德拜型向德拜型性质转变，尽管未能获得准确的德拜型响应，并作为半导体材料出现。PAPbI3 的 AC 电导率基于相关势垒跳跃 (CBH) 机制进行说明。从模量谱和直流电导率估计的活化能匹配良好，证实了弛豫行为和传导机制之间的相似性。除了所有这些之外，PAPbI3 还具有与小介电损耗相关的高介电常数，使其成为能量收集设备的潜在候选者。