利用吸收、光电流和光致发光等光谱表征并结合理论报道，分析了缺陷态丰富的铜锌锡硫半导体材料的光学带隙、带尾态和深浅杂质能级，揭示了SnZn相关的缺陷态是影响铜锌锡硫带边电子结构的关键因素，其中高浓度的中性缺陷簇[2CuZn+SnZn]能导致带隙明显窄化，而离子性缺陷簇[CuZn+SnZn]是主要的深施主缺陷态，同时存在的大量带尾态引起带边相关的光致发光峰明显红移。贫铜富锌条件下，适当减少锡含量，可有效抑制与SnZn相关的缺陷簇，并避免带隙的窄化。

The bandedge electronic structure including the optical bandgap, band-tail states, and deep/shallow donor and acceptor levels in Cu₂ZnSnS₄ semiconductor was analyzed by absorption, photocurrent and photoluminescence spectroscopy, and the theoretical reports. It is revealed that the SnZn-related defect in Cu₂ZnSnS₄ with abundant defect states is one of the key factors affecting the band-edge electronic structure. High concentration of the neutral defect cluster [2CuZn+SnZn] can narrow the band gap substantially, while the partially-passivated （ionic） defect cluster [CuZn+SnZn] is the main deep donor defect. A large number of band-tail states are responsible for the obvious red-shift of the bandedge-related photoluminescence transition energy. These detrimental defects related to SnZn can be effectively suppressed by properly reducing the Sn content in the copper-poor and zinc-rich growth condition, which also avoids the narrowing of the optical bandgap of the Cu₂ZnSnS₄ absorption layer.