Two-dimensional semiconductors having direct bandgaps and weak exciton binding are necessary for highly integrated optoelectronic devices. Herein, single-layer (SL) and bilayer (AA and AB) InSeO are proposed for the first time and studied using first-principles calculations. Both SL and bilayer InSeO are of experimental feasibility for good stability. SL and bilayer AB InSeO show moderate direct bandgaps at the HSE06 level. Their abundant visible-light absorption and weak exciton binding promise the successful generation of separated carriers. The high electron mobility of SL (∼3000 cm·V·s) and bilayer AB (∼2600 cm·V·s) suggests the possible application in electronics. The effective separation of electrons and holes is further confirmed by the huge discrepancy in carrier mobility and long-lived charge carriers. Summarily, our calculations support that InSeO is a promising candidate in ultrathin optoelectronic devices.

中文翻译：

---

单层和双层 In2SeO2：第一性原理计算中的直接带隙和减少的激子结合

具有直接带隙和弱激子结合的二维半导体是高度集成光电器件所必需的。在此，首次提出单层（SL）和双层（AA和AB）InSeO并使用第一原理计算进行研究。SL和双层InSeO均具有良好的稳定性，具有实验可行性。SL 和双层 AB InSeO 在 HSE06 水平上表现出中等的直接带隙。它们丰富的可见光吸收和弱激子结合保证了分离载流子的成功生成。SL (∼3000 cm·V·s) 和双层 AB (∼2600 cm·V·s) 的高电子迁移率表明其在电子学中的可能应用。载流子迁移率和长寿命载流子的巨大差异进一步证实了电子和空穴的有效分离。总之，我们的计算表明 InSeO 是超薄光电器件中很有前途的候选者。